Toyota Prius

Toyota Prius
Overview
Manufacturer	Toyota Motor Corporation
Production	1997–present
Body and chassis
Class	Hybrid car
Layout	FF layout

The Toyota Prius [ˈpri.əs] is a hybrid electric mid-size car developed and manufactured by the Toyota Motor Corporation.

The Prius first went on sale in Japan in 1997, making it the first mass-produced hybrid vehicle. It was subsequently introduced worldwide in 2001. The Prius is sold in more than 40 countries and regions, with its largest markets being those of Japan and North America.

According to the United States Environmental Protection Agency, the 2008 Prius is the most fuel efficient car sold in the U.S. The UK Department for Transport also reported the Prius is tied as the third least CO₂-emitting vehicle on sale in the UK.

Models

Feature		Model code
		NHW10	NHW11	NHW20
Body style		4-door Sedan	4-door Sedan	5-door Hatchback
First sales		1997	2000	2003
Battery	Modules	40	38	28
	Cells per module	6	6	6
	Total cells	240	228	168
	Volts per cell	1.2	1.2	1.2
	Total volts (nominal)	288	273.6	201.6
	Capacity amp hours	6.0	6.5	6.5
	Capacity Watt hours	1728	1778.4	1310.4
	Weight kg	57	50	45
Gasoline Engine	Power kW/HP	43/58	52/70	57/76
	Max rpm	4000	4500	5000
Electric Motor	Operating Voltage	288	273	500
	Power kW/HP	30/40	33/44	50/67
Combined	Power kW/HP	?/?	73/98	82/110

1997–2000 (model NHW10)

NHW10
Overview
Production	1997–2001
Assembly	Takaoka, later Motomachi, Japan
Body and chassis
Class	Compact car
Body style	4-door sedan
Powertrain
Engine	Toyota Hybrid System Gasoline: 1.5 L DOHC I4 13.5:1 compression 43 kW (58 hp) @ 4000 rpm 102 N·m (75 lb·ft) @ 4000 rpm Electric: 288 V motor 30 kW (40 hp) @ 940 rpm 305 N·m (225 lb·ft) @ 0 rpm
Dimensions
Wheelbase	2550 mm (100.4 in)
Length	4275 mm (168.3 in)
Width	1694 mm (66.7 in)
Height	1491 mm (58.7 in)

The first Prius, model NHW10, went on sale in December 1997. It was sold only in Japan, though it has been imported privately to the United Kingdom, Australia, and New Zealand. Many of these cars are now being exported as second-hand vehicles to New Zealand and other countries.

2001–2003 (model NHW11)

NHW11
Overview
Production	2000–2003
Assembly	Toyota City (Motomachi), Japan
Body and chassis
Class	Compact car
Body style	4-door sedan
Powertrain
Engine	Toyota Hybrid System Gasoline: 1.5 L DOHC I4 VVT-i 13.0:1 compression 52 kW (70 hp) @ 4500 rpm 110 N·m (82 lb·ft) @ 4200 rpm Electric: 273.6 V motor 33 kW (44 hp) @ 1040 rpm 350 N·m (258 lb·ft) @ 0 rpm SULEV
Transmission	1-speed planetary gear
Dimensions
Wheelbase	2550 mm (100.4 in)
Length	4308 mm (169.6 in)
Width	1694 mm (66.7 in)
Height	1463 mm (57.6 in)
Curb weight	1254.2 kg (2765 lb)

Toyota Prius Kyoto Palace patrol car

The 2001–2003 Prius for the United States market was powered by a 1.5-liter 4 cylinder gasoline engine, a permanent magnet AC electric motor, and a 274-volt nickel-metal hydride (Ni-MH) battery pack. The gasoline engine developed 70 hp (52 kW) and 82 ft⋅lbf (111 N⋅m) of torque. The electric motor generated a maximum of 44 hp (33 kW) and 258 ft⋅lbf (350 N⋅m) of torque. Japanese versions were less powerful.

The engine and motor power were increased over the previous model. Air conditioning and a continuously variable transmission were standard equipment.

In the United States, the NHW11 was the first Prius to be sold. The Prius was marketed between the smaller Echo and the larger Corolla. The published retail price of the car was US$19,995. The California Air Resources Board (CARB) classified the car as a Super Ultra Low Emission Vehicle (SULEV).

European sales began in September 2000.

The official launch of the Prius in Australia occurred in 2001 after the Sydney Motor Show.

2004–2009 (model NHW20)

NHW20
Overview
Production	2004–2009
Assembly	Tsutsumi, Japan (Toyota City) Kariya, Aichi, Japan Blue Springs, Mississippi (beginning in fall 2010)
Body and chassis
Class	Midsize car
Body style	5-door hatchback
Powertrain
Engine	Toyota Hybrid System II Gasoline: 1.5 L DOHC I4 VVT-i 57 kW (76 hp) @ 5000 rpm 115 N·m (85 lb·ft) @ 4200 rpm Electric: 500 V 50 kW (67 hp) @ 1200 rpm 400 N·m (295 lb·ft) @ 0 rpm AT-PZEV Net power: 110 hp (82 kW)
Transmission	1-speed planetary gear
Dimensions
Wheelbase	2700 mm (106.3 in)
Length	4450 mm (175.33 in)
Width	1725 mm (67.97 in)
Height	1490 mm (58.71 in)
Curb weight	1325 kg (2921 lb)

The Prius was completely redesigned into a mid-size liftback which is between the Corolla and the Camry in size. The new model is 6 inches (150 mm) longer than the previous version. Its more aerodynamic body resulted in a drag coefficient of 0.26.

The new Hybrid Synergy Drive (HSD) uses an all-electric compressor for cooling. Combined with a smaller and lighter NiMH battery, the NHW20 is more powerful and more efficient than the NHW11. Air conditioning is now operated independently of the gasoline engine, an industry first. In the U.S., the battery pack of the 2004 Prius is warranted for 100,000 miles (160,000 km) or 8 years, although Toyota has stated that they expect it to last 15 years. The warranty is instead 150,000 miles (240,000 km) or 10 years for Prius in California, and in the seven Northeastern states that have adopted the stricter California emission control standards.

It is classified as a SULEV (Super Ultra Low Emissions Vehicle) and is certified by California Air Resources Board as an "Advanced Technology Partial Zero Emission Vehicle" (AT-PZEV).

NHTSA (United States) crash testing of the 2004 Prius yielded a five star driver and four star passenger rating in the frontal collision test (out of five stars). Side crash results were four out of five stars for both front and rear seats. The car scored four out of five stars in rollover testing.

In 2004, EuroNCAP tested the Prius. It earned the following ratings: Adult Occupant: Child Occupant: Pedestrian: .

2006 Prius cut-away in Toyota showroom in Paris

Among the Prius' options are Toyota's implementation of an advanced key called Smart Key System or SKS (the feature can be user-deactivated), DVD navigation on the MFD, vehicle stability control and Bluetooth for hands-free calling. The 2006 model introduced some minor cosmetic changes, such as a higher-resolution liquid crystal display, as well as new optional features such as a rear-view camera, advanced airbags and an upgraded audio system with an auxiliary input. The 2007 Prius adds advanced and side-curtain airbags standard on all models. A Touring Edition was introduced that includes an elongated larger rear spoiler as well as larger, sharper-pointed 7-spoke 16" alloy wheels with plastic hub cap cover to protect it from scratches when parking against the curb. The Touring Edition also comes with a firmer European style tuned suspension, standard high-intensity-discharge (HID) headlights and integrated (non-HID) fog lights.

Automated parallel and reverse parking is available in Japan and Europe.

Production of the Prius for the Chinese market began in December 2005 by Sichuan FAW Toyota Motor, a joint venture with First Automobile Works.

Background

History

In 1994, Toyota executive Takeshi Uchiyamada was given the task of creating a new car which would be both fuel efficient and environmentally friendly. After reviewing over 100 hybrid designs, the engineering team settled on a hybrid engine design based on a 1974 TRW patent, but many technical and engineering problems had to be solved within the three years that the team was given to bring the car to the Japanese market, a goal they barely achieved as the first Prius went on sale in December 1997. A main problem was the longevity of the battery, which needed to last between 7 and 10 years. The solution the engineers came up with was to keep the battery pack between 60% and 40% charged, proving to be the "sweet spot" for extending the battery life to roughly that of the other car components.

The car was a modest success in Japan and after gathering several years of test data from the Japanese early adopters, the company felt it was safe to put it on sale in the U.S. and European markets in 2001. Sales were limited and customer waiting lists of up to 6 months were common during the first few years. In 2004, a complete redesign, increased production, and soaring fuel prices led to significant increases in sales.

Name

The word prius is a Latin word meaning "[to go] before." A Toyota spokesman stated that "Toyota chose this name because the Prius vehicle is the predecessor of cars to come."

Prius is not a verb but a Latin comparative adjective or adverb, the neuter nominative singular form of the adjective whose corresponding masculine and feminine nominative singular forms are prior (see also Latin declension - Irregular adverbs and their comparative and superlative forms) with meanings "ahead, in front, leading; previous, earlier, preceding, prior; former; basic". Some enthusiasts enjoy using Prii as the plural, which would be correct if prius were a regular second declension Latin noun. The actual Latin plural of the adjective is priora (Reference is slightly in error here). All of these forms are nominative case and there are several other forms for the other cases. As for the plural of Prius in English, Toyota has said that it is simply Prius and also that owners are welcome to use whatever they like.

Sales

2006 Toyota Prius used by a car share agency.

2008 Toyota Prius used as a taxi in New York City.

Toyota announced on June 7, 2007 that it had sold 1 million hybrid vehicles globally, and that of those 757,600 were Prius. Nearly 345,000 of the first 1 million hybrid cars made by Toyota were sold in Japan. In May 2008, Toyota announced that its worldwide cumulative sales of the Prius had passed the 1 million mark. The Prius, which is sold in more than 40 countries and regions, has its largest markets in Japan and North America. Nearly 60% of all Prius sales have been in North America, where 183,800 vehicles were sold in 2007. That sales pace has accelerated in early 2008, with 66,100 vehicles sold in North America in the first four months, a rate that would result in nearly 200,000 sales if continued through the entire year. In fact, Toyota sold 21,757 Prius hybrids in the United States in April, setting a record for April sales and making the Prius the third most popular vehicle in the Toyota line, trailing the Corolla and the Camry.

U.S. sales of the Prius began in August 2000. By 2001 sales there totaled 15,556, and by 2002 had reached 20,119. In 2004 sales there were 53,991, and doubled in 2005 to 107,897, about 60% of the world total of 180,000. By 2006-06-07 266,212 Prius had been sold in the U.S., and accounted for 40% of the hybrid market there in 2006. As of November 2007 Toyota has sold 510,325 Prius in the US since its initial launch in 2000. Prius gas-electric hybrid mid-size sedan reported sales of 14,212 units for a best-ever December and best-ever year-end sales of 181,221 units, up 68.9 percent over 2006.

Design and technology

See also: Hybrid Synergy Drive

The Prius is a combined hybrid (sometimes referred to as series-parallel), a vehicle that can be propelled by gasoline (petrol) and/or electric power. Components of the system include:

1. Regenerative braking, using motor-generators, which converts kinetic energy of motion into electrical energy that is stored in the traction battery and reduces wear on the brake pads;
2. A 1NZ-FXE internal combustion engine (ICE) using the more efficient Atkinson cycle instead of the more powerful Otto cycle. The gasoline engine normally shuts off during traffic stops and the accessories (including the air conditioning) are powered by the battery pack. The engine is used both to propel the vehicle and to recharge the batteries. Because of the availability of extra power from the electric motors for rapid acceleration the engine is sized smaller than usual for increased fuel efficiency and lowered emissions with acceptable acceleration;
3. Two electric motor/generators: MG1 and MG2. MG1, reversible and up to 10,000 rpm, starts the engine and provides counter torque for the Continuously Variable Transmission (CVT). MG2 provides 50 kW (67 hp) between 1,200 to 1,540 rpm and 400 N·m (295 lb·ft) torque between 0 to 1,200 rpm, contributing to performance and economy. These motor-generators are used as generators when used for regenerative braking, and as motors are capable of starting the vehicle (and gas engine if needed) and low speed (<~30 mph (48 km/h), 41 mph (66 km/h) in NHW20) travel;
4. A Hybrid Synergy Drive (HSD) unit that combines a planetary gearset that behaves like a Continuously Variable Transmission (CVT) called the Power Split Device to increase efficiency. The computer controlled HSD transaxle adjusts and blends the amount of power from the gasoline engine and electric motor-generator(s) as needed by the front drive wheels and rechargeable batteries;
5. A sealed 38-module nickel metal hydride (NiMH) battery pack providing 273.6 volts, 6.5 A·h capacity and weighing 53.3 kg (118 lb) is supplied by Japan's Panasonic. They are normally charged to 40–60% of maximum capacity to prolong battery life as well as provide a reserve for regenerative braking;
6. Wind resistance is reduced by a drag coefficient of 0.26 (0.29 for 2000 model) with a Kammback design to reduce air resistance. Lower rolling-resistance tires are used to reduce road friction;
7. A vacuum flask for storing hot coolant when the vehicle is powered off for reuse so as to reduce warm-up time (US market);
8. An EV mode (or stealth mode) that allows drivers to operate on electric power only under low-power conditions for a limited duration of time (Europe and Asian markets, aftermarket in the US). Advocates for the blind warn that the Prius is silent, and that it could be hazardous to blind pedestrians and others accustomed to engine noise to warn of a nearby vehicle;
9. Vehicle weight is reduced by the use of a flexible resin gasoline tank and by the use of aluminum instead of steel for the engine bay hood and hatchback.

THS inverter unit (from NHW11)

The computer program used in the Prius shuts off the engine when the car is stopped, is reversing, or is descending hills, thereby dramatically decreasing fuel consumption in city driving . The HSD's on-board computer program determines when and how to use the engine, motor, or both to power the car and recharge the battery so as to maximize efficiency. Typically, a gasoline engine runs inefficiently at half-throttle, creating a choking condition called pumping loss, a major reason for the inefficiency of gasoline engines compared to diesels. The Prius minimizes pumping loss by using a high torque range as much as possible with the throttle fully open. Drive-by-wire throttle control technology and Toyota's Hybrid Synergy Drive (a torque combiner, electric drive, and computer control) are essential to this engine control. In addition to the immediate benefit of reducing fuel consumption and emissions, stopping the gasoline engine also improves the performance of the catalytic converter, as the exhaust gases from an idling engine tend to cool the catalyst below its optimal temperature.

Energy monitor on the 2005 Prius multi-function display (MFD), showing energy flow to/from the engine, battery, and from the regenerative braking, as well as battery charge level.

Hybrid Synergy Drive

Typical gasoline- or diesel-engined vehicles consume fuel when the vehicle is stopped, as is common in city driving. The Prius typically shuts down the gasoline engine and runs solely off the battery pack at low speeds and when stopped. A non-hybrid car also gets worse fuel consumption in city driving because its engine is continually used to accelerate the car to driving speed and then this energy is lost to friction brakes during stop-and-go driving. The Prius recaptures some of this energy by using regenerative braking to charge its battery pack while slowing down with its motor-generators in generator mode. For acceptable acceleration the IC engine on a "standard" car typically is much larger than needed for constant-speed travel. By using both a gasoline engine and electric motors for acceleration the Prius engine can be a smaller size and still provide acceptable acceleration. This means the greatest advantages of a hybrid are mainly in city driving, though factors including driving style, air conditioning use, and short trips may offset some of this advantage. The frequent starting and stopping of the Prius engine does not cause noticeable additional wear and tear or emission problems because the electric drive motors have enough power to quickly spin the engine to optimal speed (around 1,000 rpm) before fuel is admitted.

Energy screen on the 2003 Prius

For any car, aerodynamic losses, which vary roughly as the velocity squared due to air drag are much greater on the highway than in low speed city driving. The Prius hybrid has less of an advantage in higher speed open road driving, typical of intercity driving. Nevertheless, the Prius still obtains improved fuel consumption under these circumstances since it can use a smaller and more efficient engine than would otherwise be required. The electric motor(s), powered by the battery pack, can provide the extra peak power needed for acceleration, passing and limited hill climbing. The lower weight, cross sectional area and lowest drag coefficient of a production car in the U.S. market (since the cancellation of the Honda Insight) make the Prius a very efficient highway traveler, getting Template:Mpg on the highway according to the U.S. EPA.

The environmental impact of the car's batteries has been questioned. To encourage battery recycling, dealers are paid a $200 fee for return of the car's batteries. Toyota has laboratory reports that some Prius battery packs have lasted the equivalent of 180,000 miles (290,000 km). As the cars start to age, early reports have shown that in at least some cases the batteries can last in excess of 250,000 miles (400,000 km). Individual battery longevity will vary depending upon the treatment and use history of the battery pack. A degraded battery pack will reduce performance and fuel economy, but not leave the car inoperable.

Fuel consumption and CO₂ emission

Monitor on a 2005 Toyota Prius MFD, displaying accumulative fuel economy for 59 miles (95 km) since last gas fill-up.

Fuel consumption, or fuel-efficiency in cars is generally measured as distance travelled per unit volume of fuel, as in miles per gallon (mpg), or as the volume of fuel required to cover a given distance, as in litres per 100 kilometres (L/100 km). Diesel fuel does have about an 11% higher energy density than gasoline (petrol), so that needs to be taken into account in pure energy-efficiency calculations and comparisons. Fuel-price-efficiency calculations will vary between various parts of the world, with diesel fuel pump prices being higher than gasoline prices in some countries, whilst in others it is less expensive than gasoline. A Raleigh, North Carolina firm, Advanced Vehicle Research Center, converts the Prius by adding a second battery, improving its fuel efficiency by increasing the distance it runs on electricity alone.

Official government data

United States

In the United States, the Environmental Protection Agency (EPA) test results must be posted on new vehicle windows, and are the only fuel consumption figures that can be advertised. EPA testing procedures for all vehicles were revised in 2007 in an attempt to better match what the average driver would achieve. The following data is taken from these figures: 2008 Prius Template:Mpg for city driving, Template:Mpg for highway driving, Template:Mpg combined; 2001 Prius Template:Mpg city, Template:Mpg highway. The Prius is the most efficient car available in the U.S. in 2008, based on the official rating.

United Kingdom

The official fuel consumption data, provided by the Department for Transport, rates the Prius as: Template:Mpg (Imperial) urban, Template:Mpg (Imperial) extra urban and Template:Mpg (Imperial) combined. Eleven diesel-powered cars, some of them smaller, have a better fuel-efficiency (by fuel volume) than the Prius for combined use.

According to the Department for Transport, the Prius is tied with the MINI Cooper D as the third least CO₂-emitting vehicles at 104 g/km, behind the tied Volkswagen Polo 1.4 TDI and SEAT Ibiza 1.4 TDI at 99 g/km - it is the least CO₂-emitting petrol-powered car, the Polo and the Ibiza being diesel (being these city cars).

Independent test data and comparisons with other vehicles

Several organisations have tested the fuel economy of the Prius and compared it directly with other cars.

The Prius is the most fuel efficient car that Consumer Reports has tested, giving a real-world fuel consumption of Template:Mpg for the Prius.

Consumer tests have shown petrol-electric hybrid cars in general are little more fuel-efficient (by fuel volume) than top of the range diesels. It should be noted that diesel fuel has a significantly higher energy density than the gasoline used by the Prius, and diesel is signficantly more expensive in some parts of the world, including the United States.

The UK's Sunday Times did a comparison of the Prius with another car in long distance town and country driving. The results showed that the other car, a BMW 520d SE with a Template:Auto bhp diesel engine and regenerative braking, averaged Template:Mpg (Imperial) whilst the Prius averaged Template:Mpg (Imperial) over exactly the same route. The comparison was performed on a journey of 545 miles (877 km) from London to Geneva, including 100 miles (160 km) of urban driving, about 200 miles (320 km) of driving on rural roads, and about 200 miles (320 km) of motorway driving at speeds of up to 78 miles per hour (126 km/h) on one French autoroute.

Auto Express magazine performed independent fuel efficiency tests, on public roads, on a number of hatchbacks, and in August 2007 published their list of the ten most efficient. The Prius achieved 10th place in the list, returning Template:Mpg (Imperial). A Citroën C4 Coupé 1.6 HDi got 1st place with Template:Mpg (Imperial).

Motor Trend magazine conducted a test comparing the Prius with a Honda Civic Hybrid. The Prius had the better fuel economy by 3.9 mpg–U.S. (0.53 L/100 km / 4.7 mpg–imp), achieving Template:Mpg compared to Template:Mpg for the Civic. In a similar comparison performed by Edmunds.com, the Prius managed an additional 4.5 mpg–U.S. (0.50 L/100 km / 5.4 mpg–imp) at Template:Mpg.

In a Popular Mechanics magazine diesel versus hybrid comparison of February 2005, the Prius outperformed the Volkswagen Jetta GL TDI diesel in both city and highway fuel economy.

The Prius was the overall winner of the Edmunds.com "Gas-Sipper Smackdown" fuel economy test, winning three of the five tests. The 2005 VW Jetta TDI won two of the tests. The other cars tested were the Smart Fortwo and the North American Ford Focus.

Controversies

CO₂ advertising claims

In the UK, the Advertising Standards Authority, an independent body charged with policing the rules of the advertising industry, ruled that a television advert for the Toyota Prius should not be broadcast again in the same form, having breached rules concerning misleading advertising. The advert claimed the Prius "emits up to one tonne less CO₂ per year," while on-screen text included: "1 tonne of CO₂ less than an equivalent family vehicle with a diesel engine. Average calculated on 20,000 km a year." Points of contention were the vehicles chosen for comparison, whether "up to one tonne less" adequately communicated that reductions could be lower, and whether the distance used was appropriate: 20,000 km per year is around a U.S. car's average annual driving distance, while a UK car's is 13,440 km.

An earlier complaint to the New Zealand Advertising Standards Authority, decision 03/360 2003 was also upheld. It was ruled that Toyota were in breach of the New Zealand advertising standards code of ethics, by claiming "up to 89% fewer smog forming emissions”. The figure was based on comparison with Euro 3 standards, which most new cars also met comfortably at the time.

Lifetime energy usage

The British Government and British media have requested Toyota release detailed figures for the energy use and CO₂ emissions resulting from the building and disposal of the Prius. The UK Government Car Service run 130 Priuses, and Toyota has not supplied the detailed data that they requested, to support claims that the lifetime energy usage of the Prius, including the increased environmental cost of manufacture and disposal of the nickel-metal hydride battery, are outweighed by lower lifetime fuel consumption. Toyota states that lifetime CO2 saving is 43 percent.

Political symbolism

The large number of Prius-owning progressive celebrities in 2002 prompted the Washington Post to dub hybrids "Hollywood's latest politically correct status symbol." While conservative "Prius Patriots" were also cited in 2005, the vehicle carries an image as being a car for politically liberal environmentalists. A 2007 San Francisco Chronicle article said "Prius Progressives" were becoming an archetype, quoting conservative U.S. pundit Rush Limbaugh opining that "these liberals think they're ahead of the game on these things, and they're just suckers."

Some conservatives promote use of the Toyota Prius. For example, Jim Road from What Would Jesus Drive? encouraged people to drive hybrid cars because of the damage that large SUVs can do to others.

Former CIA chief R. James Woolsey, Jr. drives a Prius because of its low fuel consumption. Woolsey noted the volatility of the Middle East, coupled with anti-US sentiment in much of the region. Noting that the high percentage of oil drilled in the Middle East gives vast profits to Middle Eastern regimes, Woolsey believes that it is a patriotic obligation to drive more efficient vehicles. In a Motor Trend magazine article, Woolsey claimed that those oil profits find their way to terrorist groups like al-Qaeda, meaning that Americans who buy inefficient vehicles would, in effect, be indirectly funding terrorism. "We're paying for both sides in this war, and that's not a good long-term strategy," said Woolsey. "I have a bumper sticker on the back of my Prius that reads, "Bin Laden hates this car."

Safety

Equipment

The following equipment is standard on U.S. models of the 2006-2009 Toyota Prius:

• Driver and front-passenger Advanced Airbag System
• Driver and front-passenger front seat-mounted side airbags and front to rear side curtain airbags
• Anti-Lock Brakes (ABS) with Electronic brakeforce distribution (EBD) and Brake Assist
• Traction Control (TRAC)
• Engine immobilizer
• Rear-seat Child Restraint System (CRS) lower anchors and top tether brackets (LATCH)
• 3-point front outboard seatbelts
• Front seatbelt pretensioners with force limiters

Optional Equipment

• Direct Tire Pressure Monitor System (standard on 2008, 2009)
• Vehicle Stability Control (VSC)

Navigation system lock-out

The Prius' onboard GPS navigation system (as well as other models, such as the Lexus, which use the same technology) is designed so that destinations cannot be entered while the vehicle is in motion. According to the owner's manual, this is done for the driver's own safety (so that he is not distracted by trying to operate the navigation system while driving the car). However, this feature has caused considerable complaints from many owners who travel with a passenger and who want to have the passenger operate the navigation system while the driver is driving. Some owners claim that this actually increases the danger, as pulling off a highway onto the shoulder to enter a destination and then attempting to merge back into traffic going at highway speeds may be more dangerous than simply having the passenger enter data while the driver concentrates on driving.

On Toyota Prius with model years 2004 and 2005, it is possible to override this lock-out by pressing the display button and then tapping the upper left, lower left, upper left, lower left, upper left, lower left corners of the screen in that order. Once that is done correctly a new menu will appear and all you have to do is hold down the override button until it beeps. However, in 2007, the override was removed for liability reasons.

Some consumers are attempting to start a petition to have the override functionality restored, many of them claiming that they were falsely informed that the override functionality was still present and that they would not have purchased the vehicle if they knew of this limitation.

Concerns

Quietness

The Wall Street Journal reported in February 2007 on concerns that quiet cars like the Prius may pose a safety risk to those who rely on engine noise to sense the presence or location of moving vehicles. Blind pedestrians are a primary concern, and the National Federation of the Blind advocates audio emitters on hybrid vehicles, but increased risks may also affect sighted pedestrians or bicyclists who are accustomed to aural cues from vehicles. In July 2007, a spokesperson for Toyota said the company is aware of the issue and is studying options. Both State and Federal legislation have been proposed and the National Highway Traffic Safety Administration held a public hearing . Different groups and companies are looking at solutions .

Government and corporate incentives

Government incentives

A number of governments have incentives that are intended to encourage hybrid car sales. In Belgium, the national government offers reductions in the purchase price of up to 15% for buying cars that have lower CO₂ exhaust.

The federal government in Canada offers to those who buy or lease hybrid cars a rebate, however the rebate program expires on December 31, 2008 without any announced extensions. Some provincial governments also offer incentives such as in British Columbia, Manitoba, Quebec, Ontario, and Prince Edward Island.

In the United Kingdom, there are both fiscal and parking-related incentives. The fiscal incentives are general; road tax is just £35 a year. Businesses can now (from 1 April 2008) claim 100% tax write-off for the Prius because the car has CO2 emissions of less than 110 grams per kilometre. The tax charge for a Prius that is provided as a company car is just 10% of its list price, rather than the heftier rates that can be up to 35% of a car's list price. Parking incentives exist in Richmond upon Thames (south west London), Westminster (Central London) for resident parking permits, Winchester (now discontinued), Manchester, and Brighton has similar plans. Drivers in London can register for an exemption from the £8 daily congestion charge Some of the incentives in the United Kingdom have been criticized in the press given that non-hybrid cars, some of which have better fuel economy, are not afforded the same incentives.

In the United States, the federal government offers a tax credit to purchasers until a certain number of cars has been sold by a manufacturer. This has ranged from US$787 to $3,150, which expired in 2007 for hybrids sold by Toyota. Some state governments, including Colorado, Connecticut, Illinois offer tax incentives. Hybrid engine automobiles are exempt from high-occupancy vehicle lane restrictions in some U.S. states.) California (currently until January 1, 2011. Los Angeles and San Jose, California had exempted hybrid cars from paying for street parking. New York State offers a special "green" version of their E-Z-Pass toll payment tag for hybrid owners who use the NYS Thruway system, which gives the owners a 10% discount on tolls. Also, the Port Authority of New York and New Jersey offers their "green E-Z-Pass" to hybrid owners, who pay $4 instead of $8 to use all the bridges and tunnels between New York and New Jersey, except in rush hours. But it is better to get the NYS Thruway green pass, since the NYS Thruway green pass allows the user to get the Port Authority Bridges and Tunnels discount, while the Port Authority Green Pass does not allow the user to get the NYS Thruway discount. (Both the Port Authority and NYS Thruway green E-Z-Passes are issued by New York State E-Z-Pass Service Centers, but users need to make sure they are issued a NYS Thruway green E-Z-Pass if they want to use both discounts.)

In the Netherlands, the government has lowered the tax for company-cars with CO₂ emissions below a certain level (such as the Prius) to 14%. The tax on all other class company-cars has been raised from 22 to 25%. As a result, in the month January alone, more than 1800 cars have been sold. The importer has already indicated that he can no longer meet the demand for the year 2008. Privately owned cars with low CO₂ emissions benefit from lower road taxes.

In Sweden, private purchasers of the Prius (or any other vehicle in the environmentally less destructive class) are awarded SEK 10,000 (roughly USD 1700, €1100) after six months of ownership, in order to stimulate sales and use of such vehicles. The subsidy program has been very successful.

Corporate Incentives

Several U.S. companies offer employees incentives. Bank of America will reimburse $3000 on the purchase of new hybrid vehicles to full- and part-time associates working more than 20 hours per week. Google, software company Hyperion Solutions, and organic food and drink producer Clif Bar & Co^{[broken footnote]} offer employees a $5000 credit toward their purchase of certain hybrid vehicles including the Prius. Integrated Archive Systems, a Palo Alto IT company, offers a $10,000 subsidy toward the purchase of hybrid vehicles to full-time employees employed more than one year.^{[broken footnote]} Clothing companies Timberland and Patagonia, law firm DLA Piper, non-profit American Jewish Committee, software publisher Topics Entertainment, and research firm ABR, Inc. are among companies offering eligible employees significant discounts on certain hybrid vehicles including the Prius.^{[broken footnote]}

Travelers Companies, a large insurance company, offers hybrid owners a 10% discount on auto insurance in most states. The Farmers Insurance Group offers a similar discount of up to 10% in most states.^{[broken footnote]}

Aftermarket products

Solar cells

Solar Electrical Vehicles is adding convex solar cells to the roof of Toyota Prius .

In May 2007 a partnership of Canadian companies lead by Hymotion altered a Toyota Prius to use solar cells to generate up to 240 watts of electrical power in full sunshine. This is reported as permitting up to 15 km extra range on a sunny summer day while using only the electric motors.

EV mode

When the vehicle is turned-on with the "start" button, it is ready to drive immediately with the electric motor, while electric pumps warm the engine with previously saved hot engine coolant, before the internal combustion engine is started. The delay between starting the car and starting the internal combustion engine is approximately seven seconds. The Asian and European versions of this vehicle provide a button labeled "EV" that maintains Electric Vehicle mode after start up, under most low-load driving conditions. This permits driving with low noise and no fuel consumption, and is advertised as a "quiet" option for short journeys, for example in residential areas at night, in the Asia manual. The car automatically reverts to normal mode if the battery becomes exhausted. The North American model does not have the "EV" button, although the "EV" mode is still supported internally by the Prius Hybrid Vehicle management computer. The PRIUS+ Project offers conversion instructions for do-it-yourselfers who wish to enable the button. Toyota has now received government approval to run on public roads for tests. Researchers at the Advanced Power and Energy Program at the University of California, Irvine and the Institute of Transportation Studies at the University of California, Berkeley will begin testing two specially made Prius and analyze driver behavior, study air quality and energy use. However, electric-only driving range remains limited to around seven miles (eleven kilometers) per charge in all-electric mode at up to 100 kilometers per hour (62 miles per hour). No date has been set for public release of EV mode, and it will not be available to the public until a great deal of additional research has been done.

Plug-in

Main article: Plug-in hybrid

Plug-in hybrids use a larger electric vehicle battery pack that is recharged from external sources in order to further reduce fuel consumption. The NiMH batteries in a production PHEV will be built to handle deeper discharge cycles without loss of lifespan such as the NiMH battery pack in the Toyota RAV4 EV. Operation of the vehicle will be very similar to a normal hybrid, except that the electric operation will be more prevalent. In the case of a Prius PHEV, on the highway, the gasoline engine will operate as before, leaving the car with the same ability to accelerate and use freeways. Current converted Prius also operate in a high speed blended mode which can reduce but not eliminate fuel consumption on the freeway. When driving in slower conditions or with light loads, the batteries will be used first in a charge-depleting mode, allowing moderate commutes at low speeds (particularly under 41 mph/65 km/h) to be driven entirely on electricity. Once the batteries have been sufficiently discharged the car will automatically revert back to the charge-sustaining mode of the current stock Prius.

Evolving from the button project, The California Cars Initiative (CalCars) converted a Prius in 2004, adding larger batteries and found out how to safely charge the batteries without affecting the hybrid system. Private companies EDrive Systems in the USA and Amberjac Projects in the UK announced plans to sell conversion kits in 2006 (pushed back to 2007). The most recent versions, such as from OEMTek.com in California use a new, patented advanced safe-format Lithium Battery from Valence Technology called Saphion. Using the advanced batteries increases the final price by an estimated US$12,000. The energy density and far more efficient utilization of these batteries provide around 20x the available power of the standard NiMH battery pack but at only double the weight. Tests show it capable of achieving > 30 miles (50 km) in all electric mode at speeds below 34 mph (55 km/h). The internal combustion engine starts only at higher speeds or when extra acceleration is needed. Fuel economy is improved to Template:Mpg - Template:Mpg depending on driving conditions. City driving may be possible without using the ICE at all, eliminating the use of almost all liquid fuel in exchange for electrical energy.

PriusPlus is a similar project evolving from CalCars, using lead-acid batteries and a do-it-yourself kit. This conversion gives a car that has Template:Mpg under normal driving conditions. All-electric mode can be used for 10–12 miles in street driving. In January 2007 issue of IEEE Spectrum, CalCars lead technical engineer, Ron Gremban, notes that drivers installing the CalCars Prius+ kit shouldn’t expect a 'positive financial payback.' The kit adds 135 kg (298 lb) to the car's weight, and increases efficiency. The lead-acid battery pack performance is reduced in cold weather, has a limited life of about 400 deep discharges, and must be recharged within a day to maintain this lifespan. The hope is, by the time the batteries need replacing, a better option will be on the market at a comparable price.

However, under certain conditions, an Argonne National Lab study showed that the Prius' blended power drivetrain made an extremely poor base for a plug-in hybrid. Specifically, with the increased use of electric power, and the internal combustion engine activating less frequently, the catalytic converter never warmed up properly. As a result, the test cars' emissions actually increased over the stock version. The same study also tested a simpler series hybrid based on a Renault Kangoo, but not as rigorously. Nonetheless, some argue that a more capable series configuration would be a better base for a PHEV than HSD because the larger electric traction motor could handle the full range of speeds, thus conferring true all-electric capabilities and completely displacing petroleum use even at highway speeds. Also, while under charge-sustaining mode the internal combustion engine would act as a continuously-running auxiliary power unit, and would not suffer the same frequent cold-start problems inherent to the Prius design.

Additionally, a study conducted by the aforementioned CalCars concluded that a plug-in Prius would only make technological sense when paired with a relatively small battery pack. As batteries grow more capacious and petroleum displacement becomes a priority over baseline efficiency, the authors wrote, the more a series design is likely to become the rational choice.

Plug in upgrades are available to the general public from Hymotion, from 6 certified installers nationwide at a cost of $9995. Hymotion claims up to 100MPG for the first 40 miles (64 km) under mostly electric power, and 4.5 hour recharge time for its A123 Systems Lithium iron phosphate battery.

Future and Plug-in version

The 2009 Prius will have only minor changes and be ready for first delivery in October 2008. The redesigned 2010 Prius, not plug-in, will be announced at the Detroit auto show, January 2009, and be available in Spring 2009. According to Edmunds, the Plug-in Prius will be available for "fleet buyers by late 2010". Toyota indicates that plug-in will be available in 2011 .

Toyota CEO Katsuaki Watanabe said in a February 16, 2007 interview that Toyota was "aiming at reducing, by half, both size and cost of the third-generation hybrid system."

A Toyota spokesman said that future Prius research "...is broad-reaching and being carried out from various angles."

Ten hydrogen powered Prius cars were delivered in November 2007 to Vistorka, a consortium of companies in Iceland.

Toyota plans to have a future option to install solar panels on the roof of its Prius, primarily to cool the car while it is parked in the sun. Expected to be available when the vehicle goes through a complete makeover as early as 2009 spring . The report states that the feature will be available on some high-end models. Some media reports have incorrectly reported that the panels will provide 2 to 5 kilowatts of electricity to power the air conditioning. In actuality, assuming reasonably-priced and commonly-used photovoltaic material, numerous engineers have calculated that the peak power available from the Prius rooftop covered completely in solar cells is approximately 250 watts. The "2 to 5 kilowatts" is likely a misquotation of the actual power consumed by the air conditioner compressor or intended to convey "2 to 5 kilowatt-hours" of use.

Toyota has announced that the Prius will be manufactured in the US in the new Blue Springs, Mississippi plant in 2010

Toyota Prius is going to include solar cells on the roof manufactured by Kyocera .

Awards

• 1997–98 Car of the Year Japan
• 2003 Scientific American names Toyota Motor Corporation as "Business Leader of the Year" ("Scientific American 50"; December, 2003) for its singular accomplishment in the commercialization of affordable hybrid cars.
• Motor Trend Car of the Year 2004
• Car and Driver magazine's Ten Best list for 2004.
• North American Car of the Year award for 2004. Nominated in 2001.
• International Engine of the Year for 2004.
• "Best Engineered Vehicle for 2004" by SAE's Automotive Engineering International magazine.
• 2005 European Car of the Year (406 points, ahead of Citroën C4 with 267 points and Ford Focus II with 228).
• 2006 EnerGuide Award (Midsize)
• 2006 Intellichoice Best Overall Value of the Year, Midsize
• 2007 Intellichoice Best in Class Winner :Best Retained Value, Lowest Fuel, Lowest Operating Costs, Lowest Ownership Costs
• Swiss government named Toyota Prius the world's greenest car in a draft study of over 6,000 cars.
• Green Engine of the Year 2008 from International Engine of the Year Awards.
• 2008 Nominated for WhatGreenCar.com Car of the Year Awards 2008, shortlisted for the UK's top Green Car Awards
• 2008 JD Power and Associates Most Dependable Compact Car

See also

• Comparison of Toyota hybrids
• List of hybrid vehicles
• Fuel economy-maximizing behaviors
• Honda Civic Hybrid
• Hybrid Synergy Drive
• Hypermiler Driving - Drivers who exceed EPA est MPG
• Hybrid electric vehicle
• Plug-in hybrid electric vehicle
• Toyota Camry Hybrid
• Toyota eCom
• ACT Hybrid Vehicle Authority

External links

• Official Toyota Prius site - UK Template:En icon
• Official Toyota worldwide website

• Toyota Prius at Curlie