Toyota Prius

Toyota Prius
Overview
Manufacturer	Toyota
Also called	Toyota Hybrid
Production	1997–present
Assembly	Toyota City, Japan
Body and chassis
Class	Hybrid car
Layout	FF layout

NHW10
Overview
Production	1997–2001
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 ft·lbf) @ 4000 rpm Electric: 288 V motor 30 kW (40 hp) @ 940 rpm 305 N·m (225 ft·lbf) @ 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)

NHW11
Overview
Production	2000–2003
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 ft·lbf) @ 4200 rpm Electric: 273.6 V motor 33 kW (44 hp) @ 1040 rpm 350 N·m (258 ft·lbf) @ 0 rpm SULEV
Transmission	1-speed CVT
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)

NHW20
Overview
Production	2004–present
Body and chassis
Class	Midsize car
Body style	5-door hatchback
Powertrain
Engine	Hybrid Synergy Drive Gasoline: 1.5 L DOHC I4 VVT-i 57 kW (76 hp) @ 5000 rpm 115 N·m (85 ft·lbf) @ 4200 rpm Electric: 500 V 50 kW (67 hp) @ 1200 rpm 400 N·m (295 ft·lbf) @ 0 rpm AT-PZEV Net power: 110 hp (82 kW)
Transmission	CVT
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)

Hybrid Synergy Drive

The Toyota Prius is a hybrid electric vehicle developed and manufactured by the Toyota Motor Corporation, and one of the first such vehicles to be mass-produced and marketed. The Prius first went on sale in Japan in 1997, and worldwide in 2001. By the end of 2003, nearly 160,000 units had been produced for sale in Japan, Europe, and North America. The Prius has won several awards, including the Car of the Year Japan (1997-98), the North American Car of the Year (2004), and the European Car of the Year (2005).

Under the United States Environmental Protection Agency's (EPA) recently revised testing procedures, the 2007 Prius is the most fuel efficient car sold in the U.S., with a combined city and highway fuel economy of Template:Mpg

Under the UK Department for Transport's "Best on CO
₂ rankings" scheme, the Prius is ranked as equal second, alongside the diesel MINI Cooper D Hatchback, and behind the diesel Volkswagen Polo 1.4 TDI 80PS, out of all the cars ranked.

Technology

The Prius is a parallel configuration hybrid, a vehicle that can run on just the combustion engine, just the electric motor, or a combination of both. Toyota's design goals are to reduce the amount of pollution and to maximise fuel efficiency. To do this, it uses a gasoline(petrol)/electric hybrid powertrain, incorporating large batteries that are charged by the gas (petrol) engine directly or by regenerative braking. Either the engine or the battery (or both) can power the vehicle, depending on conditions. This gives it the acceleration and power of a standard car having a much larger internal combustion engine. Specifically, the Prius incorporates:

1. More efficient use of the internal combustion engine (ICE), reducing fuel consumption. The 1NZ-FXE engine uses the more efficient Atkinson cycle instead of the more common Otto cycle;
2. Two electric motor/generators, MG1 and MG2 are in the transaxle. The MG2 provides 50 kW (67 hp) @ 1,200 to 1,540 rpm and 400 N·m (295 ft·lbf) torque from 0 to 1,200 rpm, which significantly contributes to performance and economy. The MG1, with rpm from -10,000 to +10,000 rpm, provides the engine starter and counter torque for the electronic Continuously Variable Transmission;
3. 50 kW IGBT inverter controlled by a 32-bit microprocessor, which efficiently converts power between the batteries and the motor/generators.
4. Lower coefficient of drag at 0.26 (0.29 for 2000 model), with a Kammback design reducing air resistance, especially at higher speeds;
5. Lower rolling-resistance tires on the 2000 model, reducing road friction;
6. Regenerative braking, a process for recovering kinetic energy when braking or travelling down a slope and storing it as electrical energy in the traction battery for later use while reducing wear and tear on the brake pads;
7. Sealed 168-cell nickel metal hydride (NiMH) battery providing 201.6 volts; supplied by Panasonic EV Energy Co
8. Continuously variable transmission — the Prius uses a computer-managed (rather than a mechanical) CVT; Toyota calls it the Power Split Device. The electric motors and gasoline engine are connected to a planetary gear set which is always engaged, and there is no shifting.
9. Flexible resin gasoline tank, reducing the amount of hydrocarbon emissions in the form of escaped gasoline vapor; (US model only)
10. Vacuum flask coolant storage system that stores hot engine coolant when the vehicle is powered off, then reuses it to reduce warm-up time. (US model only)
11. EV mode (Europe and Asian markets only, aftermarket option in the U.S.) allows the driver to select electric-only mode in low-power conditions. The vehicle can only be driven a couple of kilometers (depending on conditions) on battery power alone before the gas engine is needed.
12. Weight reduction — for example the hatch and hood/bonnet are made of aluminium instead of steel.

One reason that the Prius gets such good fuel consumption is that the ICE is smaller than in most cars this size. The ICE usually shuts off at stop lights and when backing up and descending long hills. The Prius performance remains very good because the battery/electric motor booster automatically provides adequate extra power for moderate acceleration and hill climbing. This means it drives like a traditional ICE automobile, with the on-board computer taking care of shifting power to and from the engine and motors, and automatically determining when to charge the battery, as well as the most efficient use of the engine or the electric motors (or both) based on driving conditions. This also means that one cannot use electricity from external sources. Advocates of "plug-in" hybrids consider this to be a missed opportunity. The Prius also uses its electric motor to recharge the battery during braking, with kinetic energy normally wasted as heat being recaptured. This also significantly reduces brake wear.

The engine can shut down once it has warmed up and the catalytic converter in the exhaust system has reached operating temperature. The Prius can then operate solely on electric power under low energy loads. This is sometimes referred to as "stealth mode" due to the lack of engine noise. While this further reduces fuel consumption and engine wear, advocates for the blind warn that the Prius is so quiet it could be hazardous to blind pedestrians and others accustomed to engine noise to warn of a nearby vehicle. When driving conditions demand additional power, the engine starts up automatically.

A battery module used on the Prius

The on-board computer ensures that the engine runs under the most efficient conditions. Typically, a petrol/gasoline engine runs inefficiently at half-throttle, creating a choking condition. This effect, called pumping loss, is a major reason for the inefficiency of gasoline engines compared to diesels. The Prius minimises pumping loss by running the gasoline engine at a high torque range 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.

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.

Consumption monitor on the 2005 Toyota Prius MFD, displaying fuel consumption for highway driving, in the previous 30 minutes, as well as the average fuel consumption for 59 miles since last gas fill-up.

In addition to the immediate benefit of reducing fuel consumption and emissions, stopping the combustion engine also improves the performance of the catalytic converter. In a non-hybrid vehicle the exhaust gases from an idling engine tend to cool the catalysts below their optimal temperature.

Energy screen on the 2003 Prius

The frequent starting and stopping of the engine does not cause additional wear and tear or emission problems because the drive motors have enough power to quickly spin the engine to optimal rpm (around 1,000) before the engine fires up. This avoids the wear that would occur if the engine were to run (with fuel and spark) at very low rpm.

Electric power steering

THS inverter unit (from NHW11)

For any car, aerodynamic losses due to drag are much greater on the highway than in low speed city driving. A non-hybrid car nonetheless gets worse fuel consumption in city driving because its engine is far less efficient at low power, such as when stopped in traffic, and because it must frequently dump its kinetic energy into the brakes during stop-and-go driving. The Prius gets better fuel efficiency in city dynamometer cycles because the engine can shut down instead of running at low power, and run solely off the battery at low speeds and when stopped (including the cabin air heating/cooling system and the power steering). Also, the car's kinetic energy is captured when braking and stored in the battery. According to the revised EPA tests, the Prius gets Template:Mpg in the city dynamometer tests, compared with Template:Mpg on the highway, and Natural Resources Canada estimates Template:Mpg in the city and Template:Mpg on the highway. (Owing to peculiarities of these tests, few drivers obtain these fuel consumption values in typical suburban circumstances, but "real world" performance with careful driving can come close. Typical real-world drivers get about Template:Mpg - Template:Mpg, hypermilers can get up Template:Mpg. 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 hybrid has less of an advantage in higher speed open road driving typical of intercity driving, yet obtains improved fuel consumption under these circumstances since it can use a smaller and more efficient engine than would otherwise be required (because the battery and electric motor can provide the extra peak power needed for passing and limited hill climbing).

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. The engineering team quickly settled on a hybrid engine design but many technical and engineering problems had to be solved before they could put the car into production. The team was given just three years to get the first car out onto the streets of Japan, a goal they barely achieved as the first Prius went on sale in December 1997. One of the biggest problems the team faced was the battery as the battery pack needed to last for seven to 10 years. The solution the engineers came up with was to keep the battery pack only half charged, no more than 60% charged, no less than 40%. This proved to be the "sweet spot" in extending the battery life to match (roughly) the life of the rest of the car elements.

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. market. Sales were small at first (though the waiting list was six months for the first few years in the U.S.) but picked up substantially in 2004. The Prius is considered to be a successful car for Toyota, both technically and from a marketing perspective. Whether the car has actually generated any net profit for the company is unknown. According to the head of the Prius team, the company lost money on the Prius at first.

Versions

The first Prius model, NHW10, was sold only in Japan, though personal imports have been made to the British Isles, Australia, and New Zealand. Subsequent versions have seen wider sales, increased power and reduced battery weight.

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
Petrol Engine	Power kW	43	52	57
	Max rpm	4000	4500	5000
Electric Motor	Operating Voltage	288	273	500
	Power kW	30	33	50
Combined	Power kW	?	73	82

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

2001 to 2003 Prius (NHW11)

This is a compact sedan with a distinctive front hood (bonnet). In common with the first generation Prius, it used the engine to run the air conditioning compressor - while idling, the engine would need to start every minute or so if the air conditioning was running.

It was the first Prius sold in the U.S., where it slotted between the Echo and Corolla in the company's North American lineup, and is certified as a Super Ultra Low Emission Vehicle (SULEV) by the California Air Resources Board (CARB).

It sold in relatively small numbers, it nevertheless gained wide attention and proved the market existed for a sensible hybrid vehicle as a family car.

2004 to 2007 Prius (NHW20)

2006 Prius Cut-away in Toyota Showroom in Paris

The Prius 2004 model was a complete redesign of the previous generations of Prius. The new model is larger inside and out, now a mid-size vehicle, gets even better fuel consumption, and is a hatchback.

In the U.S. market it slotted between the Corolla and Camry.

It is based on the new (second generation) Hybrid Synergy Drive (HSD or also known as THSII), replacing the earlier Toyota Hybrid System (THS) technology. In contrast to earlier generations, the 2004 model introduced an all-electric compressor for cooling, this not only allowed the use of air conditioning without the engine starting from time to time when the car was completely still, it also allowed more extensive use of the "stealth mode" (operation on electric motor only).

Its drag coefficient of 0.26 was then the second-lowest in the industry, after the Honda Insight at 0.25.

Regenerative braking was greatly improved, relying so little upon the friction-type brakes (except for panic stops) that some Toyota technicians quipped that the original brake pads might well last for the life of the car.

In general, the car remained conveniently narrow on the outside, rather flat-sided, and relatively tall (several inches taller than a Camry). The profile was more continuous, with a short sloping nose transitioning to a highly sloped windscreen and an arcing roofline ending in a cut-off Kammback. The additional height allowed a more erect seating position and a higher eye point, giving a better view of the road to the driver. There was also a surprising amount of additional rear-seat leg room, resembling that available in a much larger vehicle. Fold down rear seats with a 60/40 split made for easy carriage of most parcels. It retains a tight turning radius of 17 feet (34 feet or 10.4 meters in diameter), which when combined with a short hood is particularly useful in urban environments.

With a smaller and lower voltage NiMH battery and a boost converter to step the voltage up to 500 V, the 2004 model was more powerful (2 seconds faster in 0 to 96 km/h acceleration) and is 15% more fuel efficient than the previous generation Prius. The lower voltage also allows the traction battery to accept charge during regenerative braking down to a lower speed hence improving the energy recovery during braking. Except in short trips or extreme cold, typical commuting and mixed suburban drivers are reporting fuel consumption of Template:Mpg to Template:Mpg. Models have a 0-60 mph acceleration time of 10.1 seconds and a top speed of 105 mph (169 km/h) when using both electric and internal combustion motors simultaneously. When exclusively using its electric motor, the Prius has a 42 mph (68 km/h) top speed.

The multi-function-display (MFD) shows fuel consumption bars for each five minute segment of driving and this can encourage economical driving. The display also indicates instantaneous fuel consumption, which is useful for detecting when the vehicle has switched from electric-only to electric plus ICE. At this time it can usually be advantageous to accelerate quickly rather than lug the vehicle, in an attempt to get to a more favorable location or speed range for electric-only mode.

An option called the Smart Key System (SKS) eliminates the traditional ignition key. The "smart key," which resembles a conventional keyless entry remote, has buttons to remotely lock and unlock the door, as well as trigger the alarm system. It is not necessary to use any of the buttons to utilize the SKS. Approaching to within one meter of the car while in possession of the key (even inside a pocket or purse) causes the interior dome lights to fade in (if the switches are at the DOOR position). When the person with the key in their possession touches the inside of either of the front door handles, or the rear hatchback door handle, that door (or more) is immediately unlocked and can be opened. There are three settings in which the Smart Key System (SKS) can operate: driver's door unlocking mode, single door unlocking mode, and all doors unlocking mode. Once inside, the car may be started by pushing the "POWER" button while depressing the brake pedal, with the fob still safely tucked away inside your pocket or purse. To stop the car, push the "POWER" button again. Once parked, the car can be locked by a pushing a black button on the exterior door handle. The SKS will detect keys left inside the vehicle when powered-off, and will not allow the vehicle to be locked in this situation.

On cars which are not equipped with SKS, the driver uses the lock/unlock buttons on the fob, and puts the remote fob into a slot in the dash to allow the car to start.

The vehicle is classified as a SULEV (Super Ultra Low Emissions Vehicle), 90% cleaner than conventional gasoline-only automobiles. It comes with an Advanced Technology Partial Zero Emission Vehicle (AT-PZEV) certification by the California Air Resources Board (CARB).

As an interesting side note, an option package offered in Japan and Europe gives the Prius the ability to perform parallel and reverse parking assisted by the on-board computer — the first time such a capability has been offered on a production vehicle. Eighty percent of the Prius buyers in Japan have chosen this option. The system is not intelligent though, particularly lacking machine vision which would allow avoidance of obstructions or pedestrians, so it is very limited.

The Prius also has an optional Bluetooth hands free kit for cellphones, which uses one of the stereo's speakers in the driver door, and a microphone near the rear-view mirror. The steering wheel has a dedicated button for answering and hanging up the phone while driving. The hands free system usually comes in the highest or next-to-highest packages from the dealership. Most, but not all Bluetooth phones are 100% compatible with the Prius. Nearly all phones have the minimum functionality of using the car as a headset, but some phones also allow some or all of the following actions:

• Copy phone numbers to the Prius' (small) internal phone book (some allow them to be sent all at once).
• Display cell tower signal strength on any cellphone related screen.
• Cell phone ring tone heard through the car audio system.
• Voice dialing through car audio system.

The 2006 Prius introduced some minor cosmetic changes, along with optional features such as advanced airbags, a rear-view camera, an upgraded audio system (including a line-in port), an updated Navigation DVD with new user interface, and a higher-resolution liquid crystal display.

The 2007 Prius carries over the newer features from 2006 (also slightly higher price), while making the advanced and side-curtain airbags standard on all models. Also available is a Touring Edition 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. In addition, the Touring Edition also comes with a firmer European tuned suspension, standard high-intensity-discharge (HID) headlights and integrated (non-HID) fog lights.

Future of the Prius

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." However, plans to replace NiMH batteries with lithium-ion batteries have since then been cancelled or delayed. Lithium-ion batteries have a higher energy capacity-to-weight ratio, but cost more, and operate at higher temperatures, raising safety concerns.

It has been mentioned that a future Prius or Lexus will receive an upgrade of the petrol (gasoline) engine from 1.5 litres to 1.8 litres. A plug-in hybrid version of the Prius will allow for less fuel consumption with a bigger engine. It has also been suggested that a range of different sized models are planned, (referred to by engineers as the Prius A, B and C), rather than a single model. The first of these new models is expected in 2009. This new hybrid may carry the Lexus brand. Toyota spokesman said that future Prius research "...is broad-reaching and being carried out from various angles."

Toyota is road testing prototype plug-in hybrid vehicles (called Toyota Plug-in HV) .

Safety

Crash testing

NHTSA 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 Template:Rating-5 Child OccupantTemplate:Rating-5 Pedestrian Template:Rating-4.

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 audio cues from vehicles. In July 2007, a spokesperson for Toyota said the company is aware of the issue and is studying options.

Recalls

• In July 2006 Toyota issued a recall totaling 34,700 units covering early model Prius and Echo cars (26,200 Echo and 8,500 Prius). This recall was not related to hybrid components of the car. The connector for the crankshaft position sensor may become disconnected.
• In May 2006, Toyota announced the recall of up to 170,856 Prius vehicles because of a crack which can develop in the steering shaft if the Prius is frequently steered at full lock, or if the front tires strike the curb. The fault can affect Priuses made in 2004 through to November 2005.
• On June 1, 2005, the National Highway Traffic Safety Administration of the US started an investigation on the 33 reported cases of engine stalling when the Prius travels at highway speed. The cars were still operable under battery power for a short distance with substantial loss of power when the internal combustion engine failed to run. Toyota believes it was due to a computer programming error that was fixed in a recall (SSC-40D) issued back in September, 2004. The investigation needs to verify if all the valid reported cases occurred to cars that did not receive the software fix.
• In August 2004, Toyota began a Special Service Campaign (SSC 40G), affecting most previous-generation Prius cars manufactured between 2001 and mid-2003. This repair involves re-sealing terminals on the high-voltage battery to avoid minor electrolyte leakage. Repairs will be performed free of charge on affected automobiles.

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 (January 2004 issue)
• 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.

Controversies

Environmental impact of battery

The Mail on Sunday newspaper retracted an article linking Toyota's nickel-metal hydride battery (Ni-MH battery) production to environmental damage said to have been caused by nickel mining at a facility now owned by CVRD Inco at Sudbury, "in order to prevent further misinterpretation," and publishing in its place a rebuttal letter from Dave Rado. Rado accuses the article of inaccuracy, and notes that nickel is used for countless other purposes and that any damage occurred more than 30 years ago, long before the Prius was made. However, the article's charges were repeated by followup articles in other publications, and provoked heated debate in online forums.

A question often raised about the battery is whether it can, or will be, recycled and whether it will be source of pollution. Toyota themselves state on their website: "Toyota has a comprehensive battery recycling program in place and has been recycling nickel-metal hydride batteries since the RAV4 Electric Vehicle was introduced in 1998. Every part of the battery, from the precious metals to the plastic, plates, steel case, and the wiring, is recycled. To ensure that batteries come back to Toyota, each battery has a phone number on it to call for recycling information and dealers are paid a $200 'bounty' for each battery."

Lifetime energy cost

A 2006 study by CNW Marketing Research, Inc. calculated the overall energy cost of a Prius at US$3.25 per mile and a Chevrolet Tahoe SUV at US$2.94 per mile. It concluded that 2005 hybrids cost "significantly more in overall energy costs than conventional Internal Combustion Engine (ICE) vehicles." David Friedman of the Union of Concerned Scientists commented that the study "has been completely contradicted by studies from MIT, Argonne National Laboratory, and Carnegie Mellon's Lifecycle Assessment Group."

An article on the Better World Club website investigates the source of the statement "a Hummer is more energy efficient over its lifetime than a Prius", which it characterizes as an urban legend. It suggests that the source may be the CNW "Dust to dust" study, or follow-up articles by James L. Martin or Chris Demorro, and goes on to challenge some of the assumptions made in the study and in the mentioned articles:

• Noncomparable allocation of development costs;
• Assuming that no more Prius will be sold in future;
• Unjustified assumption the Hummer lasts for three times as many miles;
• Attributing all Sudbury nickel mining pollution to the Prius, when about 1.1 percent of the annual output is actually used
• Much greater pollution from decades-old mining methods is assumed
• Attributing unnamed costs of global transportation to Prius only; Misquoting fuel consumption; and
• Not mentioning the smaller size of the Chevy Aveo.

A critique of the 2007 version of the CNW report by the Pacific Institute concluded that "closer inspection suggests that the report's conclusions rely on faulty methods of analysis, untenable assumptions, selective use and presentation of data, and a complete lack of peer review. Even the most cursory look reveals serious biases and flaws."

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."

Many conservatives promote use of the Toyota Prius. For example, Jim Road from What Would Jesus Drive? encourages people to drive hybrid cars because of the damage that large SUVs can do to others. Driving an SUV, it is claimed, expressed an attitude not consistent with the teachings of Jesus. One could also say that conservatives that promote fiscal responsibility drive the Prius because of its economic benefits. On the other hand, the car is foreign built by a foreign company, and so this statement seems to conflict with the economic concerns that many Christians and conservatives have, especially since domestic manufacturers such as General Motors and Ford Motor Company now offer hybrid vehicles of their own.

Former CIA chief R. James Woolsey, Jr. drives a Prius because of its low petrol consumption. Woolsey claims that money that pays for imports of petrol help fund terrorism and states hostile to the United States. Ben Oliver writes the following: "By rights, Woolsey ought to drive a big, bad Hummer. Instead, he drives a Prius, and he says that if you live in a country dependent on imported oil, it's your patriotic duty to do the same. His argument is simple: It's a bad thing for transport to depend on oil when the great majority of that oil lies in volatile parts of the world whose governments are hostile to the West. Moreover, he argues that, by making the Middle East so wealthy, we're indirectly subsidizing terror. For Woolsey, the cash register at your local gas station is a collection box for al-Qaeda. 'We're paying for both sides in this war, and that's not a good long-term strategy,' he says. 'I have a bumper sticker on the back of my Prius that reads, "Bin Laden hates this car."'"

Fashion over function

The Prius's shape, although unusual, is designed to minimize aerodynamic drag. The Prius's low drag coefficient of 0.26 is influentual in making the car fuel efficient. By comparison, a Hummer H2 has a drag coefficient of 0.57. The low drag of the Prius is achieved by the teardrop shape instead of the conventional sedan shape with a boot. The conventional sedan shape encourages air flow to hit sharp edges and protrusions, thereby creating turbulence and increasing the car's fuel consumption. The smooth teardrop shape of the Prius is designed with the function of efficiency in mind. Most cars that retain the conventional sedan appearance do so because consumers are not comfortable with teardrop-shaped cars.

In spite of the efficiency goals of the Prius's shape, in 2004, industry analyst Art Spinella of CNW Marketing Research (CNWMR) said "the Prius was a fashion statement," attributing its success over the Honda Civic Hybrid to its distinctive styling, which lets "other people know the driver is driving a hybrid vehicle." The Honda Civic is available in hybrid and non-hybrid versions, making the hybrid less distinctive, though other differences from the Prius are that it is smaller and less fuel efficient.

In focus groups, Spinella said buyers reported choosing the Prius "because of its unique design, and will candidly admit they expect to receive some acclaim from friends, relatives, co-workers for their concern about the environment and/or fuel efficiency." In April 2006, noting "hybrid-vehicle sales actually have decreased since November, when fuel prices began to rise," and citing Prius sales that "dropped 23 percent (although this was actually a one time anomoly; the Federal Tax Credit had just been reduced by half and many Prius buyers had rushed to purchase before the September cut-off, skewing the numbers) over the last year," Spinella generalized that "for most people, hybrids are a fashion statement, not indicative of any real concern."

CNWMR's latest figures, first reported on the front page of the The New York Times in July 2007 and subsequently widely reported, found that just 36% of Prius buyers cited fuel economy as a prime motivator, while 57% said their main reason was that "it makes a statement about me." The latter number was under 20% in 2004, according to CNWMR.

Shortly thereafter, Washington Post columnist Robert Samuelson coined the term "Prius politics" to describe the practice of showing off rather than curbing greenhouse gas emissions, extending the concept to all ineffective feel-good measures in the broader battle against global warming.

Contrary to the fashion-over-mileage studies, a widely reported study by CNWMR, first covered in The Chicago Tribune, found considerable fluctuations in hybrid demand dependent on fuel prices. Consumers considering hybrids plummeted from 30% to 12% between late 2005 and late 2006 as fuel prices dropped, and were willing to pay a much lower premium over conventional cars in the absence of a fuel price "scare factor," according to Spinella.

Disappointing and understated fuel consumption

Hybrid owners in the U.S. were more than twice as likely to be dissatisfied with the fuel consumption of their vehicle, according to CNW Marketing Research. They reportedly found in mid 2006 that 62% of hybrid owners were dissatisfied with their fuel economy, and CNWMR's Art Spinella said those customers were unlikely to purchase another hybrid as a replacement. The figure was up from 58% in a study reported in January, 2006, and compared at that time with just 27% of conventional vehicle owners who were dissatisfied with their fuel consumption. A 2003 J. D. Power and Associates survey found poor fuel economy was the top complaint among Prius buyers, out of a total rate of complaints which was the lowest of any compact car; fuel consumption was the second most common driver complaint industrywide in this year.

While United States Environmental Protection Agency (EPA) test results, (see fuel economy in automobiles) which by law must be posted on new vehicle windows in the U.S. and are the only mileage figures that can be advertised, showed fuel consumption for the Prius in city driving as Template:Mpg in 2003, different tests by Consumer Reports estimated fuel consumption in city driving at Template:Mpg. Consumer Reports quickly retracted this assessment as flawed and issued a revised assessment giving a real-world mileage of 44 mpg for the Prius, but the original figure continues to be quoted on many web sites.

EPA testing procedures were revised in 2007, after longstanding criticism of inflated fuel consumption results. City mileage dropped an average of 12% across all vehicles, and dropped 20% for the Prius. 2007 Prius ratings were revised from Template:Mpg city, Template:Mpg highway, and Template:Mpg combined to Template:Mpg city, Template:Mpg highway, and Template:Mpg combined.

CO
₂ 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 CO
₂ per year," while on-screen text included: "1 tonne of CO
₂ 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.

Government and corporate incentives

United States

Government incentives

The Internal Revenue Service approved a series of tax deductions and credits that amount to a $3150 federal tax credit for cars purchased between January 1, 2006 and September 30, 2006. Cars purchased between October 1 2006 and March 31, 2007 may be eligible for a $1575 tax credit. Cars purchased between April 1, 2007 and September 30, 2007 may be eligible for a $787.50 tax credit. Colorado offers an alternate fuel income tax credit for the purchase of a hybrid and other alternate fuel vehicles. The credit for a 2006 Prius is $3285 and for the 2007, $3013. Used cars are eligible for the credit if the credit hasn't previously been claimed.

In Connecticut, Priuses are exempt from sales tax.

In Illinois, the state government's "Green Rewards" program offers a $1,000 incentive for new Priuses purchased through financial institutions.

Various highway lane and parking incentives are also offered in different states and municipalities. Drivers of the Toyota Prius, or other hybrid engine automobiles are allowed to drive by themselves in high-occupancy vehicle lanes in some U.S. states such as Virginia (currently until July 1, 2008, and requires a special "Clean Fuel Vehicle" license plate at $25 per year,), California (currently until January 1, 2011, requires $8 one-time fee for a decal), Florida (requires $5 per year decal), New York and Arizona. Prius and other hybrid drivers who purchased a new hybrid in San Jose, California qualified for free parking city wide until July 1 2007. Prius and other hybrid drivers qualify for free parking in metered spaces in the City of Los Angeles, California until December 31 2007.

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 offer employees a $5000 credit toward their purchase of a 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. 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.

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.

Canada

Purchases or long-term leases (12 months or longer) of new Priuses on or after 2007-03-20 qualify for a $2,000 federal rebate through the Government of Canada's ecoAUTO Rebate Program. The provinces of British Columbia, Manitoba, Quebec, and Ontario offer additional rebates of up to $2,000, while Prince Edward Island offers a rebate of up to $3,000.

Europe

United Kingdom

Prius drivers in London can register for exemption from the £8 daily congestion charge. Registration costs £10 per year.
Motoring journalist Andrew English suggests that the Prius exemption, on environmental grounds, should be a national disgrace, given that other non-hybrid cars, which have better fuel economy, are not. However, that situation may be about to change as TfL consults on new "technology neutral" criteria for the levels of charging that would give the same zero rating to the Prius and other low CO2 (sub120g/km) cars.

Westminster, in Central London, residents owning Priuses qualify for free resident parking permits, but not free parking elsewhere, which is offered for non-hybrid electric vehicles.

Winchester used to offer hybrid vehicle drivers free city-centre season car park tickets (worth up to £1,190). These included free travel on the city's park and ride buses. The city's own published regulations now only offer a 50% discount on season tickets. The more comprehensive program was discontinued in 2006 due to lack of funding.

The Manchester City Council plans to offer 25 percent off season tickets for NCP car parks, and Brighton has similar plans.

Richmond upon Thames, in south west London, charges graduated fees for resident parking permits based on CO₂ emissions, charging £50 for the first permit for a Prius compared to £300 charged for the first permit for the worst polluters.

Belgium

The Belgian government gives incentives for buying cars that pollute less, with reductions on the buying-price of up to 15% (or 4.270 eur max), based on their co² exhaust. Less poluting cars, something we all work for (Government site)

Notable facts

Taxi in Vancouver, British Columbia, Canada

Police in Ottawa, Ontario, Canada

Traffic Warden car in Örebro, Sweden.

Parking Enforcement car in Laguna Beach, CA, United States.

Battery warranty

In the U.S., the battery pack of the 2004 Prius is warranteed for 160,000 km (100,000 miles) or 8 years, although Toyota has stated that they expect it to last 15 years. The warranty is extended to 240,000 km (150,000 miles) or 10 years for Prius in California, and in the seven Northeastern states that have adopted the stricter California emission control standards.

Name

The word prius is sometimes said to be a Latin word meaning "to go before" , and a Toyota spokesman did in fact say in 2004, "Prius is a Latin word meaning 'to go before'" and "Toyota chose this name because the Prius vehicle is the predecessor of cars to come."

In fact prius is a 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;" .

Many 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. ( 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.

Miscellaneous news

• Wall Street Journal discusses Toyota's hybrid plans - Aug 10, 07
• Prius taxi surpasses 400,000 km (248,000 miles).

Sales

On 2007-06-07 Toyota announced that it had sold 1 million hybrid vehicles globally, and that of those 757,600 were Priuses.

United States

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 Priuses had been sold in the U.S., and accounted for 40% of the hybrid market there in 2006. As of October 2007 Toyota has sold 471,838 Prius in the US since launch of the first Prius in 2000.

Monthly U.S. sales

	2000	2001	2002	2003	2004	2005	2006	2007
Jan		1,298	1,954	1,606	2,925	5,566	7,654	8,299
Feb		1,198	1,481	1,968	3,215	7,078	6,547	12,228
Mar		1,378	1,763	2,532	3,778	10,236	7,922	19,156
Apr		872	1,834	1,457	3,684	11,345	8,234	13,056
May		1,126	1,648	1,233	3,962	9,461	8,103	24,009
Jun		1,534	1,369	1,069	4,219	9,622	9,696	17,756
Jul	841	1,037	1,411	657	5,230	9,691	11,114	16,062
Aug	788	1,311	1,756	299	4,393	9,850	11,177	14,055
Sep	981	862	1,382	112	4,309	8,193	10,492	12,494
Oct	829	1,580	1,775	4,085	6,123	9,939	8,733	13,158
Nov	989	1,580	1,956	5,584	5,866	7,889	8,008
Dec	1,134	1,780	1,790	4,025	6,287	9,027	17,883
Total	5,562	15,556	20,119	24,627	53,991	107,897	115,563	150,273

Aftermarket products

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. 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 Priuses 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 and 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 battery pack that is recharged from external sources in order to further reduce gas/petrol consumption. The batteries in a production PHEV will be built to handle deeper discharge cycles without loss of lifespan such as those in the Toyota RAV4 EV. Operation of the vehicle will be very similar to a normal hybrid, other than the electric operation will be more prevalent. In the case of a Prius PHEV, under high-load situations such as high-speed roads, the gasoline (petrol) 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 gasoline/petrol consumption on the freeway. When driving in slower conditions or other 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. Safe lithium-based batteries exist, eliminating all risk of run-away thermal conditions (spontaneously catch fire or explode) as seen in some laptop computer batteries.

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 use a new, patented advanced safe-format Lithium Battery from Valence Technology called Saphion. Using the advanced batteries pushes the final price to an estimated $12,000 US. The energy density and far more efficient utilisation 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.' In addition, the kit adds 135 kg to the car's weight, reducing fuel economy over the stock Prius whenever the gasoline engine is used exclusively. The lead-acid battery pack suffers 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 is on the market at a comparable price.

Hymotion is a Canadian company (recently purchased by A123systems, an advanced battery company) planning on selling a kit incorporating Lithium-Ion batteries with similar characteristics as EDrive Systems. It is currently undergoing fleet testing, and is planned for sale for 2008.

Toyota Prius in popular culture

• In Family Guy, the dog, Brian, owns a Toyota Prius. Brian is a environmentalist.

File:Http://i.treehugger.com/files/family-guy-prius-01.jpg

See also

• Comparison of Toyota hybrids
• List of hybrid vehicles
• 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

External links

• Official USA Prius web site
• Toyota Prius brochure and specifications (pdf) UK
• 24 page document on the THS II system (in PDF, 1.54 MB)