Chevrolet Volt

Chevrolet Volt
Overview
Manufacturer	Chevrolet division of General Motors
Also called	Holden Volt Opel Ampera Vauxhall Ampera
Production	Dec 2010–present
Model years	2011-present
Assembly	Detroit, Michigan, United States (Detroit/Hamtramck Assembly)
Body and chassis
Class	Compact car
Body style	5-door hatchback
Layout	Front engine, front-wheel drive
Platform	Delta II / Voltec
Powertrain
Engine	1.4 L 4-cylinder
Electric motor	One 111 kW (149 hp): One 55 kW (74 hp) permanent magnet motor/generators
Transmission	Single gear
Hybrid drivetrain	4ET50 electric drive unit
Battery	16 kWh lithium-ion battery
Range	379 miles (610 km) (EPA)
Electric range	35 miles (56 km) (EPA) 25 to 50 miles (40 to 80 km) (GM)
Dimensions
Wheelbase	105.7 in (2,680 mm)
Length	177.1 in (4,500 mm)
Width	70.4 in (1,790 mm)
Height	56.6 in (1,440 mm)
Curb weight	3,781 lb (1,715 kg)

The Chevrolet Volt is a plug-in hybrid electric vehicle manufactured by General Motors. It is also sold as a Holden and as an Opel Ampera or Vauxhall Ampera depending on markets. Sales in selected U.S. markets began in mid-December 2010 and in international markets since September 2011.

The Volt is the most fuel-efficient compact car sold in the United States, as rated by the United States Environmental Protection Agency (EPA). The Volt operates as a pure battery electric vehicle until its plug-in battery capacity drops to a predetermined threshold from full charge, at which point its gasoline engine powers an electric generator to extend the vehicle's range. The Volt's regenerative braking also contributes to the on-board electricity generation. In order to improve performance, the internal combustion engine may at times be engaged mechanically to assist both electric motors to propel the Volt.

The Chevrolet Volt has won numerous awards such as the 2009 Green Car Vision Award, 2011 Green Car of the Year, 2011 North American Car of the Year, and 2011 World Green Car, but there has been some controversy and concerns in the media. These include the extent of the federal government participation in the Volt development during General Motors' 2009 government-led bankruptcy and concerns about the battery pack fire risk after a crash.

Terminology

Further information: Hybrid vehicle drivetrain

The Society of Automotive Engineers' (SAE) definition of a hybrid vehicle states that the vehicle shall have "two or more energy storage systems both of which must provide propulsion power, either together or independently." General Motors has avoided the use of the term "hybrid" when describing its Voltec designs, even after the carmaker revealed that in some cases the combustion engine provided some assist at high speeds or to improve performance. Instead General Motors describes the Volt as an electric vehicle equipped with a "range extending" gasoline powered internal combustion engine (ICE) as a genset and therefore dubbed the Volt an "Extended Range Electric Vehicle" or E-REV. In a January 2011 interview, the Chevy Volt's Global Chief Engineer, Pamela Fletcher, referred to the Volt as "an electric car with extended range."

Basic powertrain configuration of a series hybrid vehicle like the Chevrolet Volt

According to SAE's definition the Volt is a hybrid vehicle, due to the combination of an internal combustion engine and electric motors, and its configuration can be referred to as a plug-in hybrid. The Volt operates as a purely electric vehicle for the first 25 to 50 miles (40 to 80 km), after which it functions primarily as a series hybrid, as the internal combustion engine acts primarily as a generator to power the electric traction motor. When the initial pure EV battery capacity drops below a pre-established threshold from full charge and while the Volt is operating in series hybrid mode, the Volt's control system will select the most optimally efficient drive mode to improve performance and boost high-speed efficiency.

At certain loads and speeds, 30 to 70 mph (48 to 113 km/h), the internal combustion engine may at times be engaged mechanically via a clutch to an output split planetary gearset in order to assist the electric traction motor propelling the Volt. Therefore, the Volt can operate either as an all-electric vehicle, a series hybrid or a parallel hybrid depending on the battery's state of charge (SOC) and the vehicle's operating conditions. The Volt has an automotive powertrain different from any existing car, but as a series hybrid or when in gasoline mode, the Volt operates similar to a conventional diesel-electric railroad locomotive which uses its combustion engine only to produce electricity to drive its electric traction motors, except under certain conditions when the Volt needs to improve its performance.

History

Concept vehicle

The Chevrolet Volt concept car was unveiled at the January 2007 North American International Auto Show, becoming the first-ever series plug-in hybrid concept car shown by a major manufacturer. The Volt concept vehicle had four doors with a rear liftgate and seating for four passengers. This was a significant change in design when compared to the General Motors EV1 of the 1990s, which only seated two to reduce weight and to make the necessary room for the lead-acid battery pack. The top speed was also increased on the Volt, from the electronically limited 80 miles per hour (130 km/h) to 100 miles per hour (160 km/h). The battery pack size was reduced, from about 10.6 cu ft (300 L) in volume in the EV1, to just 3.5 cu ft (100 L) in the Volt.

Then General Motors' Vice Chairman Robert Lutz has told publicly that the two-seat sports car being developed by Tesla Motors, the Roadster, and the rapid advancement of lithium-ion battery technology inspired him to push the carmaker to develop the Volt after the 2006 Detroit Auto Show. Lutz's initial idea was to develop an all-electric car, but Jon Lauckner, General Motors Vice President for Global Vehicle Development, convinced him that to avoid an expensive battery, range anxiety concerns, and lack of public charging infrastructure, they could use a smaller battery pack with a small gasoline engine driving a generator acting as a backup to extend the range, but without a mechanical connection between the gasoline engine and the drive wheels, so it would be a pure electrically driven vehicle without many of the limitations General Motors learned from the EV1 experience.

The Chevrolet Volt concept car was unveiled at the January 2007 North American International Auto Show

Most of the Volt initial design parameters defined for the development of the concept car, then referred as the "iCar" in homage to the iPod, were kept throughout the process up to the final production version. A key design parameter was a target of 40 miles (64 km) for the all-electric range, selected to keep the battery size small and lower costs, and mainly because research showed that in the U.S. 78 percent of daily commuters travel 40 miles or less. This target range would allow most travel to be accomplished electrically driven and the assumption was made that charging will take place at home overnight. This requirement translated using a lithium-ion battery pack with an energy storage capacity of 16 kWh considering that the battery would be used until the state of charge (SOC) of the battery reached 30%. This limit to the SOC was necessary in order to maintain operational performance under a wide range of environments, and to minimize the battery degradation to allow at least a ten year life span. The initial target range for the gasoline engine/generator was set between 250 to 300 miles (400 to 480 km) and the vehicle had to be family size for four or five passengers.

Another key design decision was to develop the concept car based on a new family of common powertrain components for electric propulsion, which initially was called the E-Flex Systems, “E” stands for electric drive and “Flex” for the different sources of electricity, but later was renamed Voltec drive system. The E-Flex or Voltec platform is an attempt to standardize many components of possible future electrically propelled vehicles, and to allow multiple interchangeable electricity-generating systems. The E-Flex platform has the potential to adapt the vehicles to pure battery electric, to fuel cell-powered or to several other sources of energy to create electricity on board, such as engine-generator sets (genset) fueled by gasoline, diesel, biodiesel, ethanol fuel (E100), or flex-fuel (E85). Regenerative braking would also contribute to the on-board electricity generation. On October 2006 the E-flex platform was selected for the new propulsion architecture and the name Volt was chosen by General Motors.

The Volt concept car became the first application of the E-Flex (Voltec) drive system with a combination of an electric motor, the same used in the Chevrolet Equinox Fuel Cell, a 16 kWh (58 MJ) lithium-ion battery pack with 136 kW of peak power, and a genset consisting of a small 1.0 L, 3-cylinder turbocharged flex-fuel capable engine linked to a 53 kW (71 hp) generator. General Motors called this genset an electric vehicle (EV) range extender. The vehicle was propelled by an electric motor with a peak output of 120 kW (160 hp) delivering 236 lb-ft (320 N-m) of motoring torque. The concept car featured several advanced materials from GE Automotive Plastics which allowed to reduce the vehicle weight up to 50 percent.

The Volt concept featured a 12 US gal (45 L; 10.0 imp gal) fuel capacity providing the vehicle a total driving range of around 640 mi (1,030 km), which considered a gasoline fuel efficiency of about 50 mpg_‑US (4.7 L/100 km; 60 mpg_‑imp) and a 40 mi (64 km) all-electric range. According to General Motors estimates, a daily drive of 60 mi (97 km), combined with an overnight recharge to support the first 40 all-electric miles, would yield an effective gasoline fuel economy of 150 mpg_‑US (1.6 L/100 km; 180 mpg_‑imp). General Motors also emphasized that the Volt would further reduce dependence on imported oil if E85 ethanol was used instead of gasoline to power the on-board generator engine. Robert Lutz added that if the driver used E85, "the fuel economy figure became 525 miles per (equivalent) petroleum gallon", as only 15% of gasoline is used in this blend. General Motors also noted that actual production of the Volt depended on further battery development, because the required rechargeable batteries needed to make the Volt a viable vehicle did not exist in the market and had yet to be developed. The concept car was actually powered by two 12-volt conventional car batteries, just enough power to allow the vehicle to move at low speeds in the stand.

Production model

The production design model officially unveiled on September 16, 2008, as part of General Motors centennial celebration at the Wintergarden headquarters in Detroit. The production model differed greatly in design from the original concept car. The carmaker cited necessary aerodynamic changes needed to reduce the concept cars's high drag coefficient (C_d=0.43) down to a more efficient drag coefficient of 0.28, though still somewhat higher than the Toyota Prius (C_d=0.25). Another reason was to use of General Motors' new global compact vehicle platform Delta II to keep costs reasonable, and shared with the 2010 Chevrolet Cruze. Another significant difference with the concept car is the seating, as the production Volt seats four rather than five passengers. This change was due the higher-than-usual central tunnel that runs from the front console to the rear seat that houses the car's T-shaped battery pack.

First production version of the Chevrolet Volt at the 2008 Australian International Motor Show

After the concept was put into the pipeline for production, General Motors began looking for a partner to develop the Volt's lithium-ion battery pack. The carmaker evaluated about twenty-five different battery cell chemistries and constructions from around two dozen lithium-ion battery makers around the world. Due to their more promising cell technologies, two companies were selected in June 2007, Compact Power (CPI), which uses a lithium manganese oxide (LiMn₂O₄) cell made by its parent company, LG Chemical; and Continental Automotive Systems, which uses lithium iron phosphate based cylindrical cells made by A123Systems. By the end of October 2007 CPI (LG Chem) delivered their finished battery pack prototypes, and A123 delivered theirs by January 2008. General Motors testing process was conducted at the laboratory the carmaker had created for the GM EV1 program. The battery packs included monitoring systems designed to keep the batteries cool and operating at optimum capacity despite a wide range of ambient temperatures. In order to make sure the battery pack would last ten years and 150,000 miles (240,000 km) expected for the battery warranty, the Volt team decided to use only half of the 16 kW·h capacity to reduce the rate of capacity degradation, limiting the state of charge (SOC) up to 80% of capacity and never depleting the battery below 30%. General Motors also was expecting the battery could withstand 5,000 full discharges without losing more than 10% of its charge capacity.

In April 2008 General Motors started extensive battery testing. In two years the carmaker put the battery packs to the equivalent of 150,000 real-world miles (240,000 km) and ten years of use. The durability of the battery pack was tested for a broad range of extreme ambient conditions including a shaker table to simulate potholes and a thermal chamber, to simulate temperatures varying from 116 °F (47 °C), typical of the Southwest deserts, to −40 °F (−40 °C) typical of the Alaska tundra. In April 2008 the lithium-ion battery pack was placed in Chevrolet Malibus fitted with the Volt powertrain to be used as test mules for further real-world testing. In October 2008 General Motors chose CPI (LG Chemical) to provide the battery systems for the first production version of the Volt. In July 2008 General Motors confirmed that a non-turbocharged, 1.4-liter 4-cylinder engine would be used as the range extender, and that the intention was to build it in Flint, Michigan. In April 2009, General Motors allowed journalists to test the Volt powertrain in the body of Chevrolet Cruze sedans used as test mules which lacked the range-extending generator at the GM Technical Center in Warren, Michigan.

File:2011 Chevrolet Volt NRMA cropped.jpg

Final production vehicle, the 2011 Chevrolet Volt

The first pre-production test car based on the final Volt design was built in June 2009, in Warren, Michigan, and by October 2009, 80 Volts had been built and were tested under various conditions. On March 31, 2010, the first factory-built Volt was produced at the Detroit Hamtramck Assembly Plant in order to test the production line and for quality control purposes, both of the tooling and the pre-production vehicles produced before regular production began.

Official introduction

General Motors held a ceremony at its Detroit Hamtramck Assembly Plant on November 30, 2010, to introduce the first Chevrolet Volt off the assembly line. The first Volt built for retail sale was earmarked for display at General Motors' Heritage Center museum in Sterling Heights, Michigan. The second unit was offered at a public auction, with an opening bid of US$50,000 and it was won by Rick Hendrick who paid US$225,000. The proceeds went to fund math and sciences education in Detroit through the Detroit Public Schools Foundation. Sales and deliveries began in mid December 2010.

Specifications

Drivetrain

See also: GM Voltec powertrain

Right side: power inverter on top of the electric motor used for traction; left side: the 1.4-liter gasoline engine used as a generator to keep the battery at minimum charge.

The 2011 Chevrolet Volt has a 16 kW·h / 45 A·h (10.4 kW·h usable) lithium-ion battery pack that can be charged by plugging the car into a 120-240 VAC residential electrical outlet using the provided SAE J1772-compliant charging cord. No external charging station is required. The Volt is propelled by an electric motor with a peak output of 111 kW (149 hp) delivering 273 lb-ft (368 N-m) of torque.

While driving, after the Volt battery has dropped to a predetermined threshold from full charge, a small naturally aspirated 1.4-liter 4-cylinder internal combustion engine (Opel's Family 0) with approximately 80 horsepower, burns premium gasoline to power a 55 kW (74 hp) generator to extend the Volt's range. The vehicle also has a regenerative braking system. The electrical power from the generator is sent primarily to the electric motor, with the excess going to the batteries, depending on the state of charge (SOC) of the battery pack and the power demanded at the wheels.

The Volt requires premium gasoline because the higher octane rating fuel allows the 10.5:1 compression ratio engine to maximize its fuel efficiency by 5 to 10% as compared to regular gasoline. For users who drive mostly in electric mode and to avoid maintenance problems caused by storing the same gasoline in the tank for months, the 2011 Volt has a sealed and pressurized fuel tank to avoid evaporation, and as a result, the fuel filler has to be depressurized before opening the tank. Also the engine management system monitors the time between engine running and it is programmed to prompt the driver to run past the 40-mile (64 km) all-electric range before recharging in order to consume some gasoline. If the driver does not run on gasoline, the system will automatically run the maintenance mode which starts the engine to consume some of the aging fuel and circulate the fluids within the engine. A configuration with an E85 flex-fuel capable engine is under development and is expected to be available in 2013.

Powertrain cut-away of the Volt showing both engines and the underfloor T shape tunnel where the battery pack is located

The Volt seats only four people as the battery runs down the center of the car preventing a rear bench

Operating and driving modes

Technically the Voltec drivetrain has three power converting elements:

• Primary traction motor, provides good acceleration for driving at lower speeds, its maximum output of 111 kW setting the maximum output of the whole system.
• Secondary motor/generator, assists the primary motor or works as generator capable to produce 54 kW.
• Combustion engine of 63 kW power, engaged when the batteries reach the predetermined threshold.

These units are connected via a planetary gear and electric clutches to provide power output for propulsion in four programmed operating modes:

1. Single motor electric - The primary motor runs solely on battery power, maximum propulsion power is 111 kW.
2. Dual motor electric - At higher vehicle speeds the secondary motor engages over the planetary gear such that it reduces the speed of the primary motor. This facilitates higher efficiency and better mileage for the combined system, without increasing the maximum power.
3. Single motor extended - The battery reaches its minimum charge which triggers the combustion engine. This drives the secondary motor which is now used as a generator, via the charging electronics, to keep the minimum battery charging level. The primary motor can still provide its 111 kW for short acceleration, albeit not sustained.
4. Dual motor extended - The electric motors are used again in dual configuration with increased efficiency at higher speeds. Additionally the gasoline engine contributes propulsion power via the planetary gear. While power is drained from the battery the amount is less than in mode 2 for the same propulsion power, thus extending the range.

The drivetrain platform permits the Volt to operate as a pure battery electric vehicle until its battery capacity has been depleted to a defined level, at which time it commences to operate as a series hybrid design where the gasoline engine drives the generator, which keeps the battery at minimum level charge and provides power to the electric motors. The full charge of the battery is replenished only by loading it on the electrical grid.
While in this series mode at higher speeds and loads, (typically above 30 miles per hour (48 km/h) and/or under hard acceleration) the gasoline engine can engage mechanically to the output from the transmission and assist both electric motors to drive the wheels, in which case the Volt operates as a power-split or series-parallel hybrid. After its all-electric range has been depleted, at speeds between 30 to 70 miles per hour (48 to 113 km/h), the Volt is programmed to select the most efficient drive mode, which improves performance and boosts high-speed efficiency by 10 to 15 percent.

While operating modes are switched automatically the Volt allows the driver to choose from three drive modes: normal, sport and mountain. The mountain mode, which is expected to be required only under unusual power demand conditions, increases minimum battery state of charge (SOC) to around 45%, thus maintaining performance on steep and long grades. The driver will hear more engine noise here due to the higher rate of power generation required to maintain this mode. The sport mode causes the engine to rev higher, and the response to the throttle pedal is quicker.

Battery

See also: Electric vehicle battery

The Volt's lithium-ion battery (Li-ion) battery pack weighs 435 lb (197 kg) and consists of 288 individual cells arranged into nine modules. Plastic frames hold pairs of lithium-ion cells that sandwich an aluminum cooling fin. The design and construction of that aluminum plate was critical to ensuring an even temperature distribution with no hot or cool spots across the flat, rectangular cell. The battery pack has its own cooling circuit that is similar to, but independent from, the engine cooling system.

The battery pack stores 16 kW·h of energy but it is controlled or buffered via the energy management system to use only 10.4 kW·h of this capacity to maximize the life of the pack. For this reason the battery pack never fully charges or depletes, as the software only allows the battery to operate within a state of charge (SOC) window of 65%, after which the engine kicks in and maintains the charge near the lower level. The minimum SOC varies depending on operating conditions. When more power is required, such as mountain mode, the lower limit of the SOC will raise to 45% to ensure there is enough power available.

Inlet for the electrical charger in the left side of the Chevrolet Volt with the manufacturer's provided charging cord

Despite containing near identical energy (+/- 0.5kWh), the Volt's battery pack is over 70% lighter than the EV1's original 1,310 lb (590 kg), 16.5 kW·h AC Delco lead-acid battery pack, mainly because the Volt uses higher specific energy Li-ion batteries. Li-Ion batteries are expected to become less expensive as economies of scale take effect.

Because batteries are sensitive to temperature changes, the Volt has a thermal management system to monitor and maintain the battery pack temperature for optimum performance and durability. The Volt's battery pack provides reliable operation, when plugged in, at temperatures as low as −13 °F (−25 °C) and as high as 122 °F (50 °C). Because the Volt features a battery pack that can be warmed or cooled, in cold weather the battery is preheated during charging to provide full power capability; in hot weather the battery can be cooled during charging. The Volt’s thermal management system can also be powered during driving either by the battery or engine.

The Volt's battery is guaranteed by General Motors for eight years or 100,000 miles (160,000 km), and will cover all 161 battery components. As all rechargeable batteries degrade over time, General Motors estimates the Volt battery will degrade by 10 to 30% after 8 to 10 years. The Volt’s battery management system runs more than 500 diagnostics at 10 times per second, allowing to keep track of the Volt’s battery pack in real-time, 85% of which ensure the battery pack is operating safely and 15% monitor battery performance and life.

The Volt uses a new plug specification, SAE J1772-2009, that is being proposed as a standard for electric cars. A full charge takes approximately ten to twelve hours from a standard North American 120V, 15 A household outlet and about three hours from a standard 240 VAC outlet. The Volt comes with a 20 ft (6.1 m) 120V charging cord. If plugged in, recharging can be controlled remotely through a smartphone application.

Performance

The Volt has a top speed of 100 mph (160 km/h). According to Edmunds.com road tests, the Volt's 0 to 60 mph (0–97 km/h) acceleration time is 9.2 seconds running on electric-only mode, and 9.0 seconds with the gasoline engine assisting propulsion. Motor Trend reports the Volt's quarter mile (402 m) time is 16.9 sec @ 84.3 mph (135.7 km/h), while Edmunds reports a quarter mile (402 m) time of 16.8 sec @ 81.5 mph (131.2 km/h) in electric-only operation, and 16.6 sec @ 85.5 mph (137.6 km/h) with the gasoline engine assisting. Motor Trend reports a 60 to 0 mph (97 to 0 km/h) braking distance of 112 ft (34 m) and Edmunds.com of 124 ft (38 m).

Range

Monroney label showing EPA's fuel economy and environmental comparison label for the 2011 Chevrolet Volt

United States

According to General Motors the Volt's all-electric range with fully charged batteries varies from 25 to 50 miles (40 to 80 km) depending on terrain, driving technique, and temperature. The Environmental Protection Agency (EPA) official all-electric range is 35 miles (56 km) with an energy consumption of 36 kWh per 100 miles (810 kJ/km). This range is based on the agency's five-cycle tests using varying driving conditions and climate controls. The total range with a full tank of gasoline and a fully charged battery is 379 miles (610 km) according to EPA tests.

The Volt's fuel tank capacity is 9.3 US gallons (35 L; 7.7 imp gal) and once the car runs out of fuel, the gasoline-powered generator shuts down, and the Volt taps into the battery for extra power. The reserve battery power is designed to provide an extra 3 to 4 mi (4.8 to 6.4 km) of range once the gasoline tank is depleted. When the reserve battery power is low, the Volt safely slows to a stop.

Europe

The Opel Ampera official all-electric range under the EU-approved UN ECE R101 standard for plug-in hybrids is 83 km (52 mi). Opel prefers to state that the Ampera's EV ranges is 40 to 80 kilometres (25 to 50 mi) which is confirmed in tests carried out by ADAC Motorwelt. The Vauxhall Ampera is reported to have a total range of 310 mi (500 km) miles.

Fuel economy

United States

The U.S. Environmental Protection Agency (EPA) officially rated the 2011 model year Volt's combined city/highway fuel economy in all-electric mode at 93 miles per gallon gasoline equivalent (MPG-e) (2.5 L gasoline equivalent/100 km; 112 mpg-imp gasoline equivalent) and 94 MPG-e for the 2012 model year. This rating considers a conversion factor of 33.7 kW-hr of electricity being the energy equivalent of a gallon of gasoline. The EPA rating in gasoline-only mode is 37 mpg_‑US (6.4 L/100 km; 44 mpg_‑imp). The overall combined city/highway gasoline-electricity fuel economy rating is 60 mpg_‑US (3.9 L/100 km; 72 mpg_‑imp) equivalent (MPG-e), making the Volt the most fuel-efficient compact car sold in the United States since its introduction in December 2010. For the 2012 model year, EPA revised the Volt's fuel economy ratings, increasing the combined city/highway rating in all-electric mode from 93 MPG-e to 94 MPG-e, and the highway rating was increased from 90 MPG-e to 93 MPG-e.

2012 Volt EPA/DOT Windows sticker showed potential fuel cost saving.

The Volt digital panels keep track of energy usage by fuel source and average fuel economy.

The EPA also included in the Volt's fuel economy label a table showing fuel economy and electricity consumed for five different scenarios: 30, 45, 60 and 75 miles (121 km) driven between a full charge, and a never charge scenario. This information was included in order to make the consumers aware of the variability of the fuel economy outcome depending on miles driven between charges. Under the gasoline-only scenario (never charge), the 37 mpg_‑US (6.4 L/100 km; 44 mpg_‑imp) figure results from 35 mpg_‑US (6.7 L/100 km; 42 mpg_‑imp) city driving and 40 mpg_‑US (5.9 L/100 km; 48 mpg_‑imp) on the highway.

In April 2011 General Motors reported, based on data collected through its OnStar telematics system since Volt deliveries began in December 2010, that Volt owners drive in average 800 miles (1,300 km) before they need to fill up the gasoline tank. The analysis also found that the average period between fill-ups is 30 days. In November 2011 General Motors reported that with more than 10 million cumulative miles driven by Volt owners, their data shows that around two-thirds of miles driven were in electric mode.

According to Consumer Reports in December 2011, the Chevrolet Volt fuel cost in electric mode was 3.8¢/mile, while the Nissan Leaf had a cost of 3.5¢/mi. The Volt's higher cost per mile was attributed to its heavier weight. Their estimates used the U.S. national average electricity rate of 11¢/kWh and energy consumption rates as measured on their own, unofficial tests. When comparing the Volt in range-extended mode with the four most fuel efficient gasoline-powered cars as tested by the magazine, the plug-in hybrid had a cost of 12.5¢/mi (using premium gasoline) while the Toyota Prius had a cost of 8.6¢/mi., the Honda Civic Hybrid 9.5¢/mi., the Toyota Corolla 11.9¢/mi., and the Hyundai Elantra 13.1¢/mi. The analysis also found that, on trips up to 100 mi (160 km), the Volt was cheaper to drive than the other four cars because the Volt was able to drive 35 mi (56 km) using less expensive electric power. Consumer Reports found that, using their proprietary testing, the Volt overall fuel efficiency was 99 mpg_‑US (2.4 L/100 km; 119 mpg_‑imp) equivalent (MPG-e), and using only range-extended mode the overall fuel economy was 32 mpg_‑US (7.4 L/100 km; 38 mpg_‑imp) and equivalent to the Toyota Corolla. The report noted that, as of 2011, plug-in electric cars are more expensive to buy, and the previous operating costs do not include maintenance, depreciation or other costs.

Europe

The Opel Ampera official equivalent fuel consumption under the EU-approved UN ECE R101 standard for plug-in hybrids is 1.2 L/100 km (196.0 mpg_‑US; 235.4 mpg_‑imp) (83.3 km/l). However, a leading Opel engineer prefers saying 169 Wh/km while battery-powered, and then 20 km/l petrol-powered. The ECE R101 standard weights charge-depleting mode as 76% and gasoline-only driving as 24%.

Tailpipe emissions

See also: Air pollution and greenhouse gas emissions in plug-in electric vehicles

See also: Greenhouse gas emissions in plug-in hybrids

While operating in all-electric mode the Volt produces no tailpipe emissions. However, the clean air benefit is mostly local because, depending on the source of the electricity used to recharge the batteries, air pollutant emissions are shifted to the location of the electricity generation plants. The amount of carbon dioxide emitted depends on the emission intensity of the power source used to charge the vehicle. When the Volt's battery is depleted and the gasoline-powered engine kicks in, the plug-in emissions are similar to other internal combustion engine vehicles. The amount of total local emissions depends on how much the Volt is driven in all-electric mode and how much in charge-sustaining mode.

United States

EPA rating for the Volt's tailpipe emissions is 84 grams of carbon dioxide per mile, (52.5 CO_{2 g/km), which puts the Volt ahead of the Toyota Prius in terms of low greenhouse emissions as measured at the tailpipe. CO2 emissions are produced by the internal combustion engine in extended-range mode, and only after the Volt's primary battery charge has been depleted. In the other air pollutants category, the Volt rates six out of ten, with ten being best.}

The California Air Resources Board (CARB) classified the Volt as Ultra Low Emission Vehicle (ULEV), as CARB tests do not account for the Volt electric range. With all tests conducted under conditions where the engine is running the CARB rated the Volt's carbon monoxide (CO) emissions at 1.3 g/mile (0.81 g/km), missing the limit for SULEV classification by 0.3 g/mile (0.19 g/km).

Europe

The Ampera's official EU-approved UN ECE R101 carbon dioxide emission rating is 27g/km.

Safety

The 2011 Chevrolet Volt standard features include 4-wheel anti-lock brakes with traction control; StabiliTrak electronic stability control system with brake assist; tire-pressure monitoring system; and 8 total airbags: dual-stage frontal, side-impact and knee for driver and front passenger, and roof-rail side-impact for front and rear outboard seating positions, with a passenger sensing system. There is also available an optional emergency assistance system. A safety cage, built with high-strength and ultra high-strength steel, surrounds the passenger compartment to keep the space intact in the event of a crash. Crush zones framing the trunk and the engine crumple to absorb crash energy before it reaches occupants. Door hinges and latches in harmony with door structure and its steel reinforcements to keep doors closed during an impact. The 2011 Chevrolet Volt was named "Top Safety Pick" by the Insurance Institute for Highway Safety. The Volt received the top ratings of "Good" for front, side, and rear impact crash tests, and also on rollover protection. All injury measurements except one were rated good, indicating a low risk of significant injuries in crashes according to the scale of severity employed in the IIHS’s testing. The Volt's lower rating of "Acceptable" was for torso injuries.

The Volt received a five-star overall crash safety rating from the National Highway Traffic Safety Administration (NHTSA), the highest-possible score. This rating was obtained with NHTSA's New Car Assessment Program which is used for 2011 model year vehicles.

Accident and rescue handling

In August 2010, General Motors began a training program for first responders when performing rescue duties involving the Chevrolet Volt. The program began at the 2010 Fire-Rescue International in Chicago, using a pre-production Volt for a live extrication exercise. Chicago firefighters demonstrated the sequence of tasks required to safely disable the vehicle’s powertrain and its 12-volt electrical system, which controls its high-voltage components, and then proceed to extricate injured occupants. As of January 2011, additional training workshops had taken place in several other cities corresponding to the Volt's initial launch markets. An Emergency Response Guide for the 2011 Volt was made available at its Service Technical College for use by emergency responders. The guide also describes methods of disabling the high voltage system and identifies cut zone information.

GM recommends that a Volt battery fire be fought with water rather than dry chemicals, and rates the Volt battery as having no explosion or electrocution hazard as the result of a collision. The high-voltage system is designed to shut down automatically in the event of an airbag deployment, and to detect a loss of communication from an airbag control module. During the Volt development the lithium-ion battery pack was subjected to a wide range of tests, including overcharge, discharge, vibration, excess heat and cold, short circuit, humidity, fire, crush, water immersion, salt water immersion, and nail penetration.

Warning sounds

Due to significant noise reduction typical of vehicles traveling in all-electric mode at low speeds, the Volt is fitted with a manually activated electronic warning sound system called Pedestrian-Friendly Alert System for use when the car is operating at low speeds to alert pedestrians to the car's presence.

Other features

Smartphone display for tank level and fuel range

Smartphone display of total and EV range

Connectivity

The Volt features OnStar Mobile application for owners to access vehicle information without being in or near the car. This smartphone application features the ability to check fuel efficiency as well as the vehicle's current electric range. It also helps monitor the charging, giving owners key information about the current charge level and the amount of time it will take until it is fully charged. The application also is able to control features such as locking/unlocking doors, and acts as a remote starter. A five-year OnStar Directions and Connections service was bundled into the 2011 Volt's base price, which was reduced to three years for the 2012 model year.

2011 model year

The 2011 Chevrolet Volt comes standard with cruise control; remote vehicle start-up system; 17-inch 5-spoke forged painted aluminum wheels; Bluetooth wireless technology for select phones; audio and navigation system with a center console capacitive touch panel and DVD and MP3 playback, with voice recognition; OnStar with five years of service; BOSE premium speaker system, with six speakers and sub-woofer; 30 GB hard drive for audio data storage; USB ports; three auxiliary, 12-volt, power outlets; power door locks and windows; power adjustable mirrors; programmable time of day charge control; and a 110-volt charge cord.

Available options include; 17-inch 5-spoke forged polished-aluminum wheels; rearview camera system, parking assist package; leather-wrapped steering wheel; and heated leather front seats with selectable automatic activation.

2012 model year

The 2012 Volt standard features include a remote keyless access with passive locking allowing the car to automatically lock and unlock with the key fob in close proximity of vehicle; OnStar turn-by-turn navigation for three years, and available in-dash navigation system; and Chevrolet MyLink including Bluetooth streaming audio for music and select phones. The 2012 Volt has seven option packages while the 2011 model had only three.

Production and sales

North America

Assembly of the Volt was assigned to Detroit/Hamtramck Assembly plant following the conclusion of the 2007 UAW-GM contract talks. For initial production the gasoline engine is being imported from the Opel engine plant in Aspern, Austria. In November 2010, General Motors began investingUS$138.3 million at its engine operations plant in Flint, Michigan to support increased production of the Ecotec 1.4-liter engine that is used in the Chevrolet Cruze, the upcoming 2012 Chevrolet Sonic, and the variant used in the Chevrolet Volt. The Flint plant was expected to start production of 400 engines a day in early 2011, ramp up daily production to 800 engines in late 2011, and to increase its capacity to 1,200 a day by late 2012. In May 2011, General Motors decided to invest an additional US$84 million at the Flint plant to further increase 1.4-liter engine production capacity.

Chevrolet Volt sales price by market (without any government tax credits or grants)
Country	Model year/Version	Sales price	Equivalent US$(1)	Launched/ scheduled
United States	2011 Volt	US$40,280		Dec 2010
	2012 Volt	US$39,995		Sep 2011
Canada	Chevrolet Volt	CA$41,545	US$40,720	Sep 2011
Eurozone(2)	Chevrolet Volt	€41,950	US$54,290	Nov 2011
	Opel Ampera	€42,900	US$55,520	Delayed 2012
United Kingdom	Vauxhall Ampera	£33,995	US$52,475	May 2012
	Chevrolet Volt	£33,545	US$51,785	May 2012
China	Chevrolet Volt	CN¥498,000	US$79,050	Not available
Australia	Holden Volt	Not available		4Q 2012
Notes (1): Exchange rates as of December 31, 2011. (2) Price in the Eurozone countries includes VAT

In 2010, General Motors planned an initial production for calendar year 2011 of 10,000 Volts and 45,000 units for 2012, up from the 30,000 units initially announced. In May 2011, the carmaker again raised its production targets. By mid June production was halted for about one month at the Detroit/Hamtramck Assembly plant to complete some upgrades, including the installation of new tooling, equipment and overhead conveyor systems throughout the facility. These upgrades allowed to triple the rate of Volt production and prepared the plant for 2012 Volt and Ampera production. As a result, Volt and Ampera production capacity will increase to 16,000 units in 2011, including 3,500 units for exports and 2,500 demonstration units destined to U.S. dealerships, and the rest for U.S. sales. In November 2011 GM's sales chief announced that they would not meet its sales goal of 10,000 vehicles in 2011. In 2012, global production capacity is expected to be 60,000 vehicles with an estimated 45,000 units to be delivered in the United States. Out of the 2012 production, General Motors will produce 10,000 Amperas available for sale in Europe, 6,000 destined for Opel and 4,000 for Vauxhall in the UK. In addition, 2,000 Volts will be made available for the region.

The Volt's battery cells are produced by LG Chem in South Korea and subsequently shipped to the US, where the battery packs are assembled at a purpose-built facility in Brownstown Township, Michigan owned and operated by General Motors. Compact Power, the North American subsidiary of LG Chem, is building a battery plant in Holland, Michigan to manufacture the advanced battery cells for the Volt and other carmakers, with capacity to produce enough cells for 50,000 to 200,000 battery packs per year. The US$303 million Holland plant was funded by 50% U.S. Department of Energy matching stimulus funds and is planned to open by mid 2012.

The 2011 Chevrolet Volt was officially launched on November 30, 2010 at a ceremony at the Hamtramck plant, where the first production unit for retail sale came off the assembly line. The first retail vehicle was delivered to a customer in Denville, New Jersey on December 15, 2010. GM reported it had built 12,400 Volts in total through December 2011, including dealers demos in North America and Amperas in dealerships in Europe, crash test vehicles and other unavailable Volts owned by GM.

United States

2011 Volt's frontal view

2011 Volt's rear view

The 2011 Chevrolet Volt is being sold only in selected markets due to limited initial production, as General Motors original target for 2011 was only 10,000 units. The first cars were delivered in Washington D.C., the New York City metropolitan region, California, and Austin, Texas. As of May 2011, the Volt had been launched also in Connecticut, Maryland, Michigan, New Jersey, and Virginia. Deliveries in Delaware, Florida, Georgia, Hawaii, North Carolina, Oregon, Pennsylvania, South Carolina, and Washington were expected for the third quarter of 2011. In June 2011, Chevrolet dealers nationwide began taking orders for the 2012 Volt, and deliveries in all 50 states were expected by November 2011.

The suggested retail price (MSRP) for the 2011 Chevrolet Volt in the U.S. started at US$40,280 which excluded destination freight charge, tax, title, license, dealer fees and optional equipment and before any savings due to factory incentives, tax deductions, or other available subsidies for qualifying buyers. The MSRP for the 2012 Volt starts at US$39,995 including a US$850 destination freight charge and excludes tax, title and license fees, or other available government subsidies. The base price is US$1,005 less than the 2011 model year, and General Motors explained that this price reduction is possible because of a "wider range of options and configurations that come with the expansion of Volt production for sale nationally."

Due to the capacity of the Volt's battery pack it qualifies for the maximum US$7,500 federal tax credit as specified in the Emergency Economic Stabilization Act of 2008. The federal tax credit phases out over a one year period after the manufacturer has sold at least 200,000 vehicles in the U.S. Several states also have additional incentives or rebates available for plug-in electric vehicles for qualifying buyers. The 2011 Volt price including all available regular production and premium options is US$44,600, including destination charges and before tax credits or any subsidies. For the 2012 model year the price of the Volt with all available options is US$46,265 before tax credits or any subsidies available.

Although the Volt's retail price is higher than its main competitor, the 2011 Nissan Leaf, the lease rate for the Volt is almost the same as its competitor, except that the Leaf has a lower initial payment. General Motors explained that "the apparent disparity between the Volt's sticker and lease prices is a reflection of the company's calculation that the vehicle will maintain a very high residual value after three years—significantly higher than that of the LEAF."

The price for the home charging units is US$490 plus installation costs. The Voltec home-charging unit is a 240-volt (Level II) charger, and, according to General Motors, can replenish the Volt's batteries in about four hours. Consumer Reports has advised buyers to budget up to US$2,000, as many older homes may need a substantial electrical upgrade because the U.S National Electrical Code requires that the charger have its own dedicated 220-volt, 30-amp circuit. Early buyers can benefit from the federal tax credit available for charging equipment.

Production Volts at a test drive event in Washington, D.C.

The 2011 Volt was not submitted for application to the California Air Resources Board's (CARB) Clean Vehicle Rebate Project rebate and therefore was not required to meet the 10-year 150,000-mile (240,000 km) battery warranty requirement for enhanced advanced technology partial zero-emissions vehicles (enhAT-PZEV). The Volt team explained that for the launch General Motors decided to go with a common national package which includes an 8-year 100,000-mile (160,000 km) battery warranty. For this reason owners of the 2011 Volt did not qualified for California's rebate's and free access to use carpool lanes even when traveling solo. A third package, scheduled for 2013, is under development with an E85 flex-fuel engine. General Motors engineering team commented that "introducing two or three packages of an entirely new technology set and platform at the same time wasn't an option."

In November 2011 General Motors announced that beginning in early 2012, all models sold in California will feature a new low emissions package that will allow the 2012 Chevrolet Volt to qualify as an enhanced, advanced technology –partial zero emissions vehicle (enhAT-PZEV) and have access to California’s high-occupancy vehicle lanes (HOV). The new standard California version of the Volt features a modified engine and exhaust components. The catalytic converter was modified to add a secondary air-injection pump that "streams ambient air into the exhaust stream to increase its ability to remove pollutants." Owners of a 2012 Volt with the low emissions package will be eligible to apply for one of 40,000 available HOV lane stickers issued to vehicles that qualify as a California AT-PZEV. The permits are handed out on a first-apply, first-served basis. Additionally, the new low emissions package makes the 2012 Volt eligible for owners to receive up to US$1,500 in state rebates through the state’s Clean Vehicle Rebate Project (CVRP). This incentive is in addition to the federal government’s US$7,500 tax credit. Only the 2012 Volts manufactured after February 6, 2012, will be fitted with the low emission package and be sold as standard models in California.

U.S. sales

In its first full year on sale in 2011, 7,700 Volts were sold. By early November 2011, General Motors authorized its Chevrolet dealears to sell their Volt demos to build up inventory, which amounted to 2,300 vehicles, and 600 Volts had been sold to fleet customers.

During a period from June to July 2011 there was a one-month halt in production, due to an upgrade of the Detroit/Hamtramck Assembly plant, which limited supply. After the plant retooling, the production rate reached 150 units per day four days a week by August 2011.

Resale value

In May 2011 Kelley Blue Book (KBB) projected the 2011 Chevrolet Volt resale value at just over US$17,000 after 36 months, the length of a typical lease, which represents 42% of the car's US$41,000 suggested retail price (MSRP). KBB explains that even though the residual value seems low, the projection considers that the first 200,000 Volts sold will qualify for a US$7,500 federal tax credit, which effectively reduces the MSRP to US$33,500, making the US$17,000 represent 51% of its original value after the tax credit. In comparison, KBB notes, the 2011 Toyota Prius has a projected residual of 46% after 36 months. KBB's estimate assumed gasoline price will be around US$4 per gallon in 2014.

Consumer Reports commented that their own analysis show that many Chevrolets lose about half of their purchase price after three years of ownership, and if the Volt depreciates the same, US$17,000 seems a reasonable estimate. However, Consumer Reports have noted that fuel-efficient hybrids and diesel models often depreciate far less than most vehicles, which might increase the Volt's resale value after three years above the US$17,000 estimate. Additionally, if gasoline prices continue to rise or if the tax credits expire, the demand for used Chevrolet Volts could quickly increase, raising their market value. On the other hand, if the next-generation Volt’s battery has twice the capacity and cost less, as General Motors has claimed, the first generation Volts will be obsolete when the new ones come out in 2015. Considering these assumptions, Consumer Reports considers that "at this point we believe it’s still unclear how the Volt will fare."

According to Kelly Blue Book the 2012 Volt is expected to retain 42% of its original value after 3 years and 27% after 5 years. Based on this figures, in November 2011 KBB awarded the Volt with the 2012 Best Resale Value Awards in the plug-in electric car category. KBB explains that the residual value for the Volt is lower than the market 35.5% average due to the US$7,500 federal tax credit, which lowers the transaction price and pushes down the residual value.

Canada

Chevrolet began taking orders in May 2011. with deliveries from September 2011 in major cities only. A total of 275 Volts had been sold and delivered to customers in Canada through December 2011. The Government of Ontario planned to purchase 500 Volts in 2009 for its public service fleet.

The suggested retail price (MSRP) for the 2012 Chevrolet Volt starts at CA$41,545 (US$42,423 in June 2011) which excludes any charges, fees, and optional equipment and before any available subsidies or incentives for qualifying buyers. In the Canadian market, the Volt is offered in one standard trim level with two option packages, a Premium Trim Package and a Rear Camera and Park Assist Package. Some provinces are offering Government incentives including Ontario, Quebec (both at CA$8,500 (US$8,680) and British Columbia has announced their new LiveSmart BC program in which the Chevrolet Volt qualifies for a CA$5,000 incentive/rebate as well as CA$500 towards charging equipment.

Europe

The European version of the Volt, the Opel Ampera (known as the Vauxhall Ampera in the United Kingdom), was unveiled at the Geneva Auto Show in March 2009 and also was exhibited at the 2009 Frankfurt Auto Show.

Opel is developing the battery control modules for the Ampera at the Opel Alternative Propulsion Center Europe in Mainz-Kastel, Germany. The production version of the Ampera was unveiled at the 2011 Geneva Motor Show.

Opel Ampera frontal view

Opel Ampera rear view

The main differences between the Volt and the Ampera are in their styling. The Ampera has a distinctive front and rear fascia, with a large cut-out in the rear bumper. The Opel Ampera features more stylized alloy wheels as standard, and the side skirts are body-colored rather than black. In the inside there are only minor differences and both versions share the same exact powertrain and battery pack. A key operational difference is that the Ampera will have four drive modes, one more than the Volt. The additional option is "City Mode", which adapts battery management to the needs of commuter travel. City mode or "battery hold" engages the range-extender immediately, allowing to save the energy currently stored in the battery, and when switched off, the range-extender stops and the Ampera is then able to use the energy saved in the battery for pure electric driving, for example for traveling urban areas or restricted zones, such as the European low emission zones or to allow the Ampera to qualify for an exemption of the London congestion charge and Milan Area C.

The Opel Ampera will benefit from several subsidies and tax breaks available for plug-in electric vehicles in several European countries. According to Opel, as of June 2011 around 5,000 customers across Europe have reserved an Ampera, with 3,000 reservations from corporate customers. The Ampera is assembled at the Detroit/Hamtramck Assembly plant, Michigan. For 2012 General Motors plans to manufacture 10,000 Amperas for sale in Europe, 6,000 destined for Opel and 4,000 for Vauxhall in the UK, plus an additional 2,000 Volts will be made available for the region. The carmaker will target the Ampera for business fleet market and local government agencies, where Opel has a strong customer base, while the Volt will be aimed at retail customers. Deliveries of the Opel Ampera to dealerships began in Belgium, France, Germany, the Netherlands and Switzerland in December 2011. Deliveries were scheduled to begin by late 2011, but Opel decided to delay customer deliveries until the NHTSA completes its investigation of the Volt's battery fire risk after a crash. The first deliveries of the Chevrolet Volt in Europe took place on November 30, 2011, to the U.S. Embassy in France. Deliveries of the right-hand drive Vauxhall Ampera continue as originally scheduled for May 2012 in the UK.

In February 2011 Opel announced that the Ampera will be offered for a uniform price throughout the Eurozone at €42,900 (US$58,000 in February 2011) including VAT, but prices by country may vary due to the trim levels that will be offered in each market. The Chevrolet Volt also has a uniform price that starts at €41,950 (US$54,290 in December 2011) including VAT.

In the UK, the Ampera pricing starts at £33,995 including VAT (US$54,770 in July 2011) before discounting the £5,000 Plug-in Car Grant and deliveries are scheduled to begin in May 2012. The Chevolet Volt will also be available in the UK at a cost of £33,545 (US$54,050 in July 2010) before the government grant. All Volts in the UK will come standard with leather interior.

China

In September 2010, General Motors unveiled the Chevrolet Volt under its Chinese name of 沃蓝达 (Wo Lan Da) and delivered the first two Volts for use as part of Expo 2010 Shanghai China's transportation fleet. The Volt is scheduled to go on sale in China by late 2011. However, according to General Motors, the Chinese government is refusing the Chevrolet Volt to qualify to up to US$19,300 in government subsidies unless GM agrees to transfer intellectual property to a joint venture with a Chinese automaker for at least one of the Volt’s three core technologies: electric motors, complex electronic controls, and power storage devices, whether batteries or a fuel cell. General Motors is negotiating with the Chinese government to let the Volt qualify for the subsidies without the technology transfer. As of November 2011 the subsidies are available only for electric cars made by Chinese automakers.

General Motors announced that the imported Volt's price starts at CN¥498,000 (around US$78,000 as of January 2012) and initial sales will be limited to eight Chinese cities: Beijing, Shanghai, Hangzhou, Suzhou, Wuxi, Guangzhou, Shenzhen and Foshan. GM explained that 13 dealerships were selected in the eight cities, and they were chosen because these "cities have more elites who are inclined to try new technologies and lead the fashion tide." The first Volts, out of the 10-vehicle demonstration fleet, arrived in China by late December 2011. The demonstration program will take place in Beijing, Tianjin and Shanghai.

Other markets

Australia

Holden Volt

The Holden Volt is scheduled to be launched in the Australian market by late 2012. Opel has also stated that it is considering selling the Ampera in Australia alongside the Volt when the brand is launched in 2012.

In November 2011 the first Holden Volt arrived in Australia for a series of evaluation journeys. Holden has announced that the Volt has undergone numerous modifications to better suit it to Australian roads, although the test vehicles are left-hand drive.

Brazil

General Motors do Brasil announced that it will import from five to ten Volts to Brazil during the first semester of 2011 as part of a demonstration and also to lobby the federal government to enact financial incentives for green cars. If successful, General Motors would adapt the Volt to operate on ethanol fuel, as most new Brazilian cars are flex-fuel.

Japan

In December 2010, General Motors announced plans to introduce the Volt in limited numbers into Japan in 2011 for technology and market test purposes. Exports for retail sales will depend on the results of this trial.

Related concept cars

The Cadillac Converj, unveiled at the 2009 North American International Auto Show, shares the Volt's Voltec powertrain.

Cadillac Converj

The Cadillac Converj is a plug-in hybrid concept car first unveiled at the 2009 North American International Auto Show and incorporates the propulsion system from the Chevrolet Volt, including the Voltec powertrain. In August 2011, General Motors announced that the Converj concept will go into production as the Cadillac ELR.

Volt MPV5

At the 2010 Auto China show General Motors unveiled the Chevrolet Volt MPV5 Concept. The Volt MPV5 is a plug-in crossover hybrid and has a top speed of 100 mph (160 km/h) and an electric range of 32 miles (51 km). The MPV5 integrates design elements from the Volt, with a body style very similar to the Chevrolet Orlando and four inches larger than its predecessor, Chevrolet HHR.

Controversies and criticism

EPA fuel economy testing

Typical EPA's new fuel economy label for an extended-range electric vehicle like the Chevrolet Volt (top), and for a blended or series-parallel plug-in hybrid (bottom)

In 2008, General Motors was concerned about how the United States Environmental Protection Agency (EPA) would test the Volt to determine its official fuel economy rating. The controversy centered on whether, by including a gasoline engine, the Volt should be classified as a hybrid rather than an electric car as claimed by General Motors. If tested with the same EPA tests used by other hybrids, the Volt's EPA fuel economy rating would be around 48 mpg_‑US (4.9 L/100 km; 58 mpg_‑imp) due to the current EPA test for hybrids disallowing vehicles from boosting their mpg rating using stored battery power. General Motors stated that the Volt is an entirely new type of vehicle which the EPA's current fuel economy tests were not suited to rate and that a new test should be devised for this emerging class of hybrid-electrics. General Motors also advocated for a more simplified mpg calculation method to take into account the range of a plug-in hybrid while running solely on electricity. Because the Volt can travel 40 miles (64 km) on batteries alone, GM argued that most drivers with a daily commute of less than that distance would drive only in electric mode, so long as they recharged their vehicle at work or at home overnight.

The EPA official rating issued in November 2010 included separate fuel economy ratings for all-electric mode and gasoline-only mode, with an overall combined city/highway gasoline-electricity fuel economy rating of 60 mpg_‑US (3.9 L/100 km; 72 mpg_‑imp) equivalent (MPG-e). To address the variability of the fuel economy outcome depending on miles driven between charges, EPA also included in the Volt's fuel economy label a table showing fuel economy and electricity consumed for five different scenarios driven between a full charge, and a never-charge scenario. According to this table the Volt's fuel economy goes up to 168 mpg_‑US (1.40 L/100 km; 202 mpg_‑imp) equivalent (MPG-e) if driven 45 miles (72 km) between full charges. Also, in recognition of the multiple operating modes that a plug-in hybrid can be built with (all-electric, blended, and gasoline-only), for the new fuel economy and environment label that will be mandatory in the U.S. beginning in model year 2013, EPA and the National Highway Traffic Safety Administration (NHTSA) issued two separate fuel economy labels for plug-in hybrids. One label is for extended-range electric vehicles, like the Chevy Volt, with two modes: all-electric and gasoline-only; and a second label for blended mode that includes a combination of all-electric, gasoline and electric operation, and gasoline only, like a conventional hybrid vehicle.

EPA fuel economy rating

On August 2009, General Motors released its estimated city fuel economy rating for the Volt of 230 mpg_‑US (1.0 L/100 km; 280 mpg_‑imp) of gasoline plus 25 kW·h/100 mi (560 kJ/km) of electricity using the EPA's proposed method for evaluating plug-in hybrids. The U.S. Environmental Protection Agency (EPA) issued a statement clarifying that the "EPA has not tested a Chevy Volt and therefore cannot confirm the fuel economy values claimed by GM." On July 2010, General Motors recognized that their estimate was based on a formula that never got official approval, and they were awaiting EPA's decision on how the equivalent fuel economy of plug-in hybrids will be estimated.

The official EPA rating was issued in November 2010 EPA and became the agency's first fuel economy label for a plug-in hybrids. The EPA rated the 2011 Volt combined fuel economy at 93 miles per gallon gasoline equivalent (MPG-e) in all-electric mode, and 37 mpg_‑US (6.4 L/100 km; 44 mpg_‑imp) in gasoline-only mode, for an overall combined fuel economy rating of 60 mpg_‑US (3.9 L/100 km; 72 mpg_‑imp) equivalent (MPG-e). The label also shows the combined city-highway fuel economy in all-electric mode expressed in traditional energy consumption units, rating the Volt at 36 KWh per 100 miles (160 km).

Production cost and sales price

In 2009, the Presidential Task Force on the Auto Industry said that "GM is at least one generation behind Toyota on advanced, “green” powertrain development. In an attempt to leapfrog Toyota, GM has devoted significant resources to the Chevy Volt." and that "while the Chevy Volt holds promise, it is currently projected to be much more expensive than its gasoline-fueled peers and will likely need substantial reductions in manufacturing cost in order to become commercially viable."

A 2009 Carnegie Mellon University study found that a PHEV-40 will be less cost effective than a HEV or a PHEV-7 in all of the scenarios considered, due to the cost and weight of the battery. Jon Lauckner, a Vice President at General Motors, responded that the study did not consider the inconvenience of a 7 miles (11 km) electric range and that the study's cost estimate of US$1,000 per kWh for the Volt's battery pack was "many hundreds of dollars per kilowatt hour higher" than what it costs to make today."

President Barack Obama behind the wheel of a new Chevy Volt during his tour of the General Motors Auto Plant in Hamtramck, Michigan

After the Volt's sales price was announced in July 2010, there was concerned expressed of the launch price of the Volt and its affordability and resulting popularity, especially when the federal subsidies of US$2.4 billion were taken into account in the development of the car.

General Motors CEO Edward Whitacre Jr. rejected as "ridiculous" criticism that the Volt's price is too expensive. He said that "I think it's a very fair price. It's the only car that will go coast to coast on electricity without plugging it in, and nobody else can come close." Despite the federal government being the major GM shareholder due to the 2009 government-led bankruptcy of the automaker, during a press briefing at the White House a Treasury official clarified that the federal government did not have any input on the pricing of the 2011 Chevrolet Volt.

There have also been complaints regarding price markups due to the initial limited availability in 2010 of between US$5,000 to US$12,000 above the recommended price, and at least in one case a US$20,000 mark up in California. Even though the carmaker cannot dictate vehicle pricing to its dealers, GM said that it had requested its dealers to keep prices in line with the company’s suggested retail price.

In May 2011 the National Legal and Policy Center announced that some Chevrolet dealers were selling Volts to other dealers and claiming the US$7,500 federal tax credit for themselves. Then the dealers who bought the Volts sell them as used cars with low mileage to private buyers, who no longer qualify for the credit. General Motors acknowledged that 10 dealer-to-dealer Volt sales had taken place among Chevrolet dealers, but the carmaker said they do not encourage such practice.

Battery pack fire risk

Chevrolet Volt that caught fire after the test pole in June 2011. Top: before the NHTSA test pole. Below: After the fire.

In June 2011 a Volt that had been subjected by the National Highway Traffic Safety Administration (NHTSA) to a 20 mph (32 km/h) side pole impact crash test followed by a post-impact rollover, caught fire three weeks later in the test center parking lot, burning nearby vehicles. The battery was found to be the source of the fire. After the fire, both Chevrolet and the NHTSA independently replicated the crash test and a subsequent vehicle rotation procedure to test for any fluid leakage, but in their first attempt they could not reproduce the conditions under which the battery pack ignited. The NHTSA said it had "concluded that the crash test damaged the Volt’s lithium-ion battery and that the damage led to a vehicle fire that took several weeks to develop." In further testing of the Volt's batteries carried out by NHTSA in November 2011, two of the three tests resulted in thermal events. One battery pack was rotated 180 degrees within hours after it was impacted and began to smoke and emit sparks after rotation. In the other case, the battery pack that was crashed-tested one week earlier and that had been monitored since the test caught fire. The NHTSA then took an uncommon step on November 25, 2011 and opened a formal safety defect investigation "without any data from real-world incidents" to examine the potential risks involved from intrusion damage to the battery pack in the Chevrolet Volt. After the initial Volt fire, the NHTSA examined the Nissan Leaf and other plug-in electric vehicles and said its testing “has not raised safety concerns about vehicles other than the Chevy Volt.”

Chevrolet Volt after being subjected to the NCAP pole test on May 12, 2011 at the MGA test facility.

As a result of this investigation, GM announced that it would offer any Volt owner who has concerns another GM car while the federal investigation is taking place. In December 2011, the company said that if necessary they were prepared to recall all the vehicles and repair them upon determination of the cause of the fires, and also announced they would buy back the car if the owner was too afraid of the potential for a fire. GM's CEO also said that it may be necessary to redesign or make changes to the battery pack depending on the recommendations from federal officials. As of December 1, 33 Volt owners in the U.S. and 3 in Canada had requested a loaner car. As of December 5, General Motors reported that a couple dozen Volt owners had requested the carmaker to buy back their cars, and the company had already agreed to repurchase about a dozen. Before the carmaker agrees to buy back each vehicle, other options are explored as GM primarily wants to provide loaner cars, but "if the only way we can make them happy is to repurchase it, then we will," a GM spokeman said. General Motors explained that the buy back price includes the Volt purchase price, plus taxes and fees, less a usage fee based on how many miles the car has been run. As of January 5, 2012, GM reported that around 250 Volt owners had requested either a loaner vehicle or a potential buyback.

The NHTSA also said it was working with all automakers to develop postcrash procedures to keep occupants of electric vehicles and emergency personnel who respond to crash scenes safe. Additionally, NHTSA advised to be aware that fires may occur a considerable amount of time after a crash. General Motors said the first fire would have been avoided if GM's protocols for deactivating the battery after the crash had been followed. These protocols had been used by GM since July 2011 but were not shared with the NHTSA until November 2011. In another statement the carmaker stated that they “are working with other vehicle manufacturers, first responders, tow truck operators, and salvage associations with the goal of implementing industrywide protocols.”

NHTSA testing of the Volt's battery pack

Arcing event during manual rollover of post crashed Volt's battery, November 24, 2011.

Customer deliveries of the Opel Ampera in Europe were delayed until the NHTSA completes its investigation of the Volt's battery fire risk to make sure the vehicle is safe. However, deliveries of the first Chevrolet Volts in Europe began in France in November 2011. Deliveries of the Vauxhall Ampera in the UK continue as scheduled for May 2012.

Battery enhancements

On January 5, 2012, General Motors announced that it would offer a customer satisfaction program to provide modifications to the Chevrolet Volt to reduce the chance that the battery pack could catch fire days or weeks after a severe accident. The carmaker described the modifications as voluntary enhancements and stated that neither the car nor the battery was being recalled. General Motors determined the June fire was the result of a minor intrusion from a portion of the vehicle into a side section of the battery pack. This intrusion resulted in a small coolant leak inside the battery of approximately 50 ml. When the vehicle was put through a slow roll, where it’s rotated at 90 degree increments, holding in each position for about five minutes, an additional one liter of coolant leaked. With the vehicle in the 180 degrees position (upside down), the coolant came in contact with the printed circuit board electronics at the top of the battery pack and later crystallized. Three weeks later this condition, in combination with a charged battery, led to a short circuit that resulted in the post-crash fire.

General Motors explained the modifications will enhance the vehicle structure that surround the battery and the battery coolant system to improve battery protection after a severe crash. The safety enhancements consist of strengthening an existing portion of the Volt’s vehicle safety structure to further protect the battery pack in a severe side collision; add a sensor in the reservoir of the battery coolant system to monitor coolant levels; and add a tamper-resistant bracket to the top of the battery coolant reservoir to help prevent potential coolant overfill. The additional side safety structural pieces have a total weight of 2 to 3 lb (0.91 to 1.36 kg), and their function is to spread the load of a severe side impact away from the battery pack, eliminating the possibility of intrusion into the pack.

During December 2011 GM conducted four crash tests of Volts with the reinforced steel and upgraded cooling system, resulting in no intrusion to the battery and no coolant leakage. On December 22, 2011, the NHTSA also subjected a modified Volt to the same test that led to the original fire, with no signs of the damage that is believed to have been the cause. The NHTSA said “the preliminary results of the crash test indicate the remedy proposed by General Motors today should address the issue of battery intrusion” though its investigation remained open. General Motors declined to say how much the modifications would cost.

All 12,400 Chevrolet Volts produced until December 2011, including all Amperas in stock at European dealerships, will receive the safety enhancements. Since production was halted during the holidays, the enhancements will be in place when production resumes in early 2012. Sales will continue and dealers will modify the Volts they have in stock, either before or after they are sold. General Motors sent a letter to Volt owners indicating that Chevrolet will contact them with more details about the service effort scheduled to begin in February 2012.

NHTSA findings

On January 20, 2012, the National Highway Traffic Safety Administration closed the Volt's safety defect investigation related to post-crash fire risk. The agency concluded that "no discernible defect trend exists" and also found that the modifications recently developed by General Motors are sufficient to reduce the potential for battery intrusion resulting from side impacts. The NHTSA also said that "based on the available data, NHTSA does not believe that Chevy Volts or other electric vehicles pose a greater risk of fire than gasoline-powered vehicles." The agency also announced it has developed interim guidance to increase awareness and identify appropriate safety measures regarding electric vehicles for the emergency response community, law enforcement officers, tow truck operators, storage facilities and consumers.

House of Representatives hearing

On December 6, 2011, the chairman of the Subcommittee on Regulatory Affairs, Stimulus Oversight and Government Spending, U.S. Representative Jim Jordan announced that hearings to be held in January 25 2012 to investigate why the NHTSA opened a formal investigation only five months after the first postcrash battery fire occurred in June. The subcommittee of the House Committee on Oversight and Government Reform wanted to determine if government officials, including from NHTSA, purposely held back information on the Volt fire for political reasons. Both Daniel Akerson, General Motors CEO, and David L. Strickland, NHTSA administrator, denied any wrongdoing.

Other incidents

During 2011 two other Volts were involved in garage fires, one in Barkhamsted, Connecticut, another in Mooresville, North Carolina. In both cases the fire marshal's report concluded the Volt was not the cause of the fire.

Reception

Awards and recognition

The Volt has received awards from multiple organizations:

U.S. organizations

The Chevrolet Volt won the 2011 Motor Trend Car of the Year award.

• 2009 Green Car Vision Award by the Green Car Journal at the Washington Auto Show for "a bold and far-reaching approach that promises to bring an exceptionally fuel efficient model to consumers at reasonable cost."

• 2011 Car and Driver Ten Best Cars. For the first time ever Car and Driver magazine included an electrically powered car among its 10 best.

• 2011 Motor Trend Car of the Year. The magazine commented that "In the 61-year history of the Car of the Year award, there have been few contenders as hyped – or as controversial – as the Chevrolet Volt."

• 2011 Green Car of the Year by Green Car Journal. The magazine editors explained that "This award welcomes a new genre of mass-production electric vehicles to the consumer market, with the Volt as the first-ever electric vehicle to take top prize."

• 2011 Automobile of the Year by Automobile Magazine. The editors commented that the Volt "...is genuinely an all-new car, in the most simplistic sense as well as in the greater notion that the Volt is unlike any vehicle we have ever driven."

• 2011 North American Car of the Year announced at the 2011 North American International Auto Show. Forty-nine American and Canadian automobile writers chose the Volt. The nominees were judged based on "innovation, design, safety, handling, driver satisfaction and value".

• Listed among the 2011 Greenest Vehicles of the Year by the American Council for an Energy-Efficient Economy.

• Listed among the 2011 Best Green Cars by Mother Earth News.

• 2011 Edison Award - Gold in the Transportation Category, Personal Transportation Segment.

• 2012 Best Resale Value Award in the category of electric cars by Kelley Blue Book.

• The Volt ranked first in Consumer Reports' list of owner-satisfaction based on its 2011 Annual Auto Survey, with 93% respondents who owned the Volt saying they definitely would purchase that same vehicle again. The magazine noted that the Volt had been on sale for just a few months at the time of the survey, and also clarified that the survey took place before the National Highway Traffic Safety Administration investigation regarding the Volt's battery fire risk.

• 2012 Total Cost of Ownership Award in the electric car category, granted by Kelly Blue Book for the lowest projected costs during initial five-eear ownership period in its category.

International organizations

• 2009 Festival Automobile International selected the Chevrolet Volt for the 2009 Grand Prize for Environment.

• 2011 World Green Car announced at the 2011 New York Auto Show.

European organizations

• 2011 Overall Winner of What Car? Green Awards, granted by the UK magazine to the Vauxhall Ampera.

• 2012 Car of the Year in Denmark. In October 2011, 18 Danish motor journalists chose the Opel Ampera as "Car of the Year 2012" by a wide margin, despite being more expensive than the family cars the award usually goes to.

Reviews and test drives

The following tables summarize the results of long-term tests reported by specialized media.

Chevrolet Volt

Summary of the Volt's all-electric range and fuel economy results published by the specialized press and industry analysts. Only the EPA results should be used for comparison purposes.1
Reviewer	Driving condition		All-electric range	Fuel economy Gasoline only	Fuel economy EV mode (MPG-e)	Comments
EPA 2011 model year	EPA five-cycle tests: varying driving conditions and climate controls		35 mi (56 km)	37 mpg‑US (6.4 L/100 km)	93 mpg‑US (2.5 L/100 km) equivalent	All ratings combined city and highway Overall combined gasoline-electric fuel economy rating of 60 mpg‑US (3.9 L/100 km; 72 mpg‑imp) equivalent (MPG-e)
EPA 2012 model year	EPA five-cycle tests: varying driving conditions and climate controls		35 mi (56 km)	37 mpg‑US (6.4 L/100 km)	94 mpg‑US (2.5 L/100 km) equivalent	All ratings combined city and highway EV mode city 95 mpg‑US (2.5 L/100 km) equivalent EV mode highway 93 mpg‑US (2.5 L/100 km) equivalent Energy consumption of 36 kWh per 100 miles.
Consumer Reports	Long term test		35 mi (56 km)	32 mpg‑US (7.4 L/100 km)	99 mpg‑US (2.4 L/100 km) equivalent	Several driving conditions
	Normal daily commute under cold winter time		25 mi (40 km)	30 mpg‑US (7.8 L/100 km)	n.a.	Outdoor temperatures averaged about 20 to 30 °F (−7 to −1 °C). Almost1,000 miles (1,600 km). Average combined 53 miles per US gallon (4.4 L/100 km)
Motor Trend	Long term test		Over 35 mi (56 km)	n.a	n.a.	Normal everyday driving over 16,503 miles (26,559 km) during 8 months. Average combined fuel economy 48.9 mpg‑US (4.81 L/100 km) equivalent. Energy consumption 68.7 kW-hr/100 mi.
	Extended test on cold winter time (February-mid April)		22 to 30 mi (35 to 48 km)	n.a	75.3 mpg‑US (3.12 L/100 km) equivalent	Over 3,090 miles (4,970 km), 2,259 city/831 highway. Combined gasoline/electricity average fuel economy of 49.26 miles per US gallon (4.775 L/100 km) equivalent. Average cost US$0.08/mi (US$0.05/km). Maximum EV range: 39.4 miles (63.4 km) at 50 °F (10 °C).
Edmunds.com	Typical traffic driving		33 mi (53 km)	31.4 mpg‑US (7.5 L/100 km)	n.a	Over 1,000 km. Lowest range 27 mi (43 km) and highest 39 mi (63 km) Energy consumption 39.0 kilowatt-hours per 100 miles.
Car and Driver	City streets		n.a.	n.a.	122 mpg‑US (1.93 L/100 km) equivalent	EV mode only using climate control. Downtown Ann Arbor, 43 mi (69 km) at an average speed of 15 mph (24 km/h).
	Suburban commute		n.a.	n.a.	119 mpg‑US (1.98 L/100 km) equivalent	EV mode only using climate control, over 42 mi (68 km) at an average speed of 46 mph (74 km/h).
	Highway		n.a.	40 mpg‑US (5.9 L/100 km)	n.a.	Michigan Peninsula over 894 mi (1,439 km) at an average speed of 70 mph (110 km/h). Gasoline and electric using climate control.
Popular Mechanics	Two-lane roads under "lead-foot" style driving, A/C off		31 mi (50 km)	n.a.	n.a
	City streets under normal style driving, A/C on		35 mi (56 km)	31.7 mpg‑US (7.4 L/100 km)	n.a.
	Highway only		33 mi (53 km)	36 mpg‑US (6.5 L/100 km)	n.a	Over 600 miles (970 km) at an average speed of 78 mph (126 km/h)

Notes:

1. ^ The EPA tests used a reproducible methodology to produce results that can be compared between vehicles and test sites. The remainder of the results were obtained using un-controlled driving cycles and are comparable neither to each nor between different vehicles.

See also

• Chevrolet Spark EV
• GM Voltec platform
• Electric car
• EV Project
• General Motors EV1 – all-electric car from the 1990s
• General Motors XP-883 – plug-in hybrid vehicle from 1969
• General Motors Hy-wire – hydrogen powered
• General Motors Sequel – hydrogen powered
• Genset trailer
• Government incentives for plug-in electric vehicles
• List of modern production plug-in electric vehicles
• Magna International
• Opel Flextreme – Diesel plug-in hybrid by Opel

External links

• Official website
• Official Opel Ampera site
• Official Vauxhall Ampera site
• Chevrolet Volt Emergency Respond Guide
• NHTSA Interim Safety Guidance for Vehicle Owner/General Public
• NHTSA Interim Safety Guidance for Law Enforcement/Emergency Medical Services/Fire Department
• NHTSA Chevrolet Volt Battery Incident Report Overview, January 2012 - DOT HS 811 573
• Production of Volt on YouTube
• Test drive of Volt preproduction vehicle on YouTube

Bibliography

• Edsall, Larry (2010). Chevrolet Volt: Charging into the Future. Motorbooks. ISBN 978-0760338933.
• Fletcher, Seth (2011). Bottled Lightning: Superbatteries, Electric Cars, and the New Lithium Economy. Hill and Wang, New York. ISBN 978-0809030538.