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Prius redirects here. For the Japanese personal computer, see Hitachi Flora Prius.
The Toyota Prius is the world's first commercially mass-produced and marketed hybrid automobile. It 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. In Latin, prius means "before" or "first". The Prius (2000 to 2003 model years) is certified as a Super Ultra Low Emission Vehicle (SULEV) by the California Air Resources Board (CARB). With the 2004 model, the Prius was redesigned as a midsize hatchback, and certified as an Advanced Technology Partial zero-emissions vehicle (AT-PZEV). For North America, it used to slot between the Echo and Corolla in the lineup, but now slots beween the Corolla and Camry since the second generation of this vehicle was released.

Prius has won numerous awards including Car of the Year awards for Europe, Japan and North America. See the Award section.

How it works

The Prius has been called a true hybrid vehicle, designed from the bottom up. Toyota's goal for the Prius was to reduce the amount of pollutants it produced and to be as energy-efficient as possible. They used several methods to try to achieve this goal, including:
  1. More efficient use of the internal combustion engine (ICE), reducing gasoline consumption. The 1NZ-FXE engine uses the more efficient Atkinson cycle instead of the more common Otto cycle;
  2. Two electric motor/generators, providing 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 contribute to performance & economy;
  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), 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 traveling 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;
  8. Continuously variable transmission — the Prius does not use a typical CVT; Toyota calls it the Power Split Device. The electric motors and gas engine are connected to a planetary gear set which is always engaged, and there is no shifting.
  9. Flexible resin gas tank, reducing the amount of hydrocarbon emissions in the form of escaped gasoline vapor;
  10. Vacuum flask coolant storage system that stores hot engine coolant, then reuses it to reduce warm-up time.
  11. Weight reduction — for example the hatch and hood are made of aluminium instead of steel.
Touted advantages of the Prius over previous energy-efficient designs include never needing to be plugged in, as all energy ultimately comes from the gasoline engine. This means it drives like a traditional ICE automobile, with the onboard 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; some consider this to be a serious disadvantage. The Prius recovers energy that would be otherwise wasted: when braking, the car's kinetic energy is partly recovered to recharge the battery instead of being wasted as heat. This also 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 be driven on electric power only; this is sometimes referred to as "stealth mode" due to the lack of engine noise. This further reduces gasoline consumption and wear and tear on the engine. When driving conditions demand additional power from the engine, it starts up automatically.

The on-board computer ensures that the engine runs under the most efficient conditions. Typically, a gasoline engine runs inefficiently when throttle is half-open, creating a choking operation conditions. This effect, called pumping loss, is a major reason for the inefficiency of gasoline engines compared to diesel engines. The Prius minimizes the pumping loss by running the gasoline engine at high torque range with throttle fully open. Drive-by-wire technology and CVT are essential in this engine control.

As well as the immediate benefit of reducing fuel consumption and emissions, stopping the engine also improves the performance of the catalytic converter, as in a normal vehicle the exhaust gases from an idling engine tend to cool the catalysts below their optimal temperature.

Unlike in conventional automobiles, frequent starting up and shutting down of the engine causes neither additional wear and tear nor emission problems, because the drive motors have enough power to quickly and smoothly spin the engine to optimal rpm (around 1,000) before the engine actually begins to "fire up". This avoids wear when the engine is "running" (with fuel and spark) at very low rpm, as happens in most vehicles.

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 mileage 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 the city because the engine can shut down instead of running at low power, and run solely off the battery at low speeds and when stopped. Also, the car's kinetic energy can be captured when braking, and stored in the battery. According to EPA tests the 2004-2006 Prius gets 60 mpg in the city, compared with 51 on the highway, and Natural Resources Canada estimates 58.8 mpg (4.0 L/100 km) in the city and 56.0 (4.2 L/100 km) on the highway. [http://oee.nrcan.gc.ca/transportation/tools/fuelratings/ratings-results.cfm 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 highway driving, but it can still 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 hill climbing.

2004 to 2006 Prius

The Prius 2004 model was a complete redesign of the previous generations of Prius. The new model is based on the new (second generation) Hybrid Synergy Drive (HSD or also known as THSII), replacing the earlier Toyota Hybrid System (THS) technology. The first generation (1997 to 2003) could not run its air conditioning 100% of the time unless the engine was running. While idling, the engine would need to start every minute or so if the air conditioning was running. In contrast, 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 smaller 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.

The 2004 Prius emerged as a midsize car with more room than the previous compact, redesigned as a "five-door" model (four doors plus a rear hatch). 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 much more continuous, with a short sloping nose transitioning to a highly sloped windshield 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.

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, with 60 miles per US gallon (4.3 L/100 km) city and 51 miles per US gallon (4.7 L/100 km) highway (according to the EPA) *. When driven appropriately, commuting and mixed suburban drivers are reporting fuel consumption of 45 to 50 miles per US gallon (5.2 to 4.7 L/100 km). See also *

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 + 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.

A Smart Key System (SKS) option 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 system. Approaching to within one metre 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 either of the front doors, or the rear hatchback door, that door is immediately unlocked and can be opened. There are three settings in which the Smart Key System (SKS) can operate with: 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 system will detect keys left inside the vehicle when powered-off, and will not allow the vehicle to be locked in this situation.

There is no conventional ignition switch which needs to be turned to start the Prius, that function having been replaced by a simple round "POWER" button on the dashboard. With the SKS models, the driver only needs to sit down inside the vehicle (with the fob in their possession), press the brake with their foot and push the "POWER" button to start the vehicle. 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 CARB (California Air Resources Board).

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. *

When the vehicle is turned-on with the "start" button, it is ready to drive immediately with the electric motor, before the internal combustion engine is started to heat-up the emissions control system (including the catalytic converter). 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 startup, 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 high-voltage management computer. While some have speculated that EV mode was not included on North American models in the interest of retaining the warranted battery life of 100,000 miles (160,000 km) in the US—150,000 miles (240,000 km) in California and several other states—engineers note that EV mode is automatically overridden when the battery requires recharging from the internal combustion engine. The Prius is designed to protect the battery from extreme discharge as well as over-charge and will utilize the engine as-necessary to maintain the optimum conditions for a long battery life. In addition to information at online discussion groups, the PRIUS+ Project offers instructions for do-it-yourselfers who wish to enable the button, and after-market components provider Coastal Electronic Technologies offers a kit.

Evolving from the button project, The California Cars Initiative (CalCars) converted a Prius in 2004, adding larger batteries, and private companies EDrive Systems in the USA and Amberjac Projects in the UK announced plans to sell conversion kits in 2006. CalCars initiated efforts to promote the idea of plug-in hybrids to be built by automakers, and documented the emissions benefits of plug-in hybrids not only on California's clean power grid but also on the national (50% coal-fueled) power grid.

Passengers of the Prius can use their Bluetooth-enabled cellphone via the car's audio system without taking the phone out of their pocket.

The 2006 Prius introduced some minor cosmetic changes, along with advanced airbags, a rear-view camera, an upgraded audio system, and a new higher-resolution LCD display.

Versions

The first Prius model, NHW10, was sold only in Japan, though personal imports have been made to the United Kingdom, 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.

Awards

Criticism

The Prius has been criticized by some for its aesthetics and handling characteristics. In addition to this, manufacturing the electric components, aluminium parts, and the NiMH battery pack requires a significant amount of energy. Toyota's life cycle assessment shows that the amount of energy required to manufacture a Prius is higher than that of a similar gasoline powered vehicle, although the energy saving during its operational life pays-back this initial energy overhead *. While a landmark in both automotive design and marketing, the Prius still uses regular gasoline unlike other alternative fuel vehicles. When compared to plug-in hybrid electric vehicles, the fuel and emissions saving of the Prius is modest.

Some drivers complain that they do not get anywhere close to the EPA fuel economy estimate. Although most vehicles do not achieve EPA estimates unless driven under the same strict EPA conditions, critics claim that the discrepancy of the EPA estimate and actual fuel economy is larger for the Prius than other vehicles. Since the Prius needs to run its engine longer for warming-up, its fuel efficiency deteriorates in extreme cold conditions. In 2006, EPA announced a plan to implement a new way to calculate more realistic fuel economy for all vehicles in 2008. By the European method, the combined fuel economy of the Prius is 4.3 l/100 km or 55mpg By Japanese 10.15-mode fuel economy, the Prius achieves 33 km/l or 78mpg[http://toyota.jp/prius/spec/spec/index.html.

For other criticism common to all types of hybrid vehicles such as maintenance, disposal, weight and complexity, please see the trade-off section of hybrid vehicle.

Notable facts

  • Drivers of the Toyota Prius, or other hybrid engine automobiles are allowed to drive by themselves in Carpool (High Occupancy Vehicle) lanes in some US states such as Virginia (currently until July 1, 2007, and requires a special "Clean Fuel Vehicle" licence plate at $25 per year *), California (requires $8 one-time fee for a decal), Florida (requires $5 per year decal), and New York.
  • Los Angeles city, Santa Monica and San Jose, California allow free parking at meters for hybrid vehicles within the posted time limits, including the Prius.
  • The Prius is among the multitude of cars available in the video game Gran Turismo 4.
  • Prius drivers in London, UK, are exempt from the £8 ($14) daily congestion charge (requires £10 per year registration).
  • Prius drivers in Winchester, UK, used to qualify for free parking at a number of the city's car parks (season ticket worth ~ £800 per annum). This has now been discontinued due to lack of funding.
  • Due to the success of both the engineering and sales of the Prius, in 2005, Toyota has released a hybrid V-6 engine for the Lexus RX400h and a hybrid engine version of the Highlander.
  • The NHW20 Prius fuel tank holds 45 litres (11.9 US gal), although the internal bladder in American models limits the fill, giving a range of up to 600 miles (1,000 km). The fuel tank capacity for a European NHW11 without the bladder is 50 litres.
  • 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.
  • Starting with the 2004 model, Toyota is now producing the Prius on a standard mass production assembly line, resulting in one being produced every minute instead of one every 8 to 10 minutes. The use of a standard assembly line has dropped the manufacturing cost significantly, allowing Toyota to deliver a substantially upgraded model, which in turn has generated publicity and popularity. The limiting factor in Prius (and Lexus RX400h) production now appears to be third party component availability, particularly batteries.
  • The battery pack of the 2004 Prius is guaranteed 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 extended to 150,000 miles (240,000 km) or 10 years for Prius in California and several other states that adopted the Californian emission control standards.
  • In May 2005, Finnish anti-virus firm F-Secure Corp. has tested a Prius for Bluetooth vulnerabilities in the on-board mobile telephony and computer systems and found the car has performed "admirably".
  • 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 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 reported cases occurred to the cars that did not receive the software fix. Some supporters argued that 33 cases (of which some were duplicate reports and/or valid out-of-gas conditions) among 75000+ cars sold was not an alarming percentage figure compared to the millions other auto makers have recalled. Besides, the Prius is safer than any other car with a failed engine, as the Prius can still run with its electric motor until it can stop at a safe location.
  • In May 2006, Toyota announced the recall of up to 320,000 Priuses 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.
  • In June 2002 the Prius became the first ever hybrid car to complete an FIA rally. Driven by UK journalist Nik Berg and co-driver Tim Bampton the Prius finished the 2002 Midnight Sun to Red Sea Marathon in 15th place after completing 5,000 miles in 20 days of rallying.

Famous owners

Fictional owners

Sales

As of June 2006, over 60,000 Prius have been sold in California.

Car rental

Many Toyota dealerships offer car rentals, allowing prospective buyers to try the Prius. EV Rental Cars, in partnership with Fox Rent-a-Car, offers the Prius for rent at the airports in Phoenix, San Francisco, San Jose, Oakland, Orange County, Los Angeles, and San Diego.

It can also be rented from Hertz at the airports in San Francisco, occasionally San Jose, and downtown Austin (709 East 10th Street).

The Toyota Prius can be rented in Canada from Discount Car Rental * and from Via Route *.

In British Columbia, Vancouver's Co-operative Auto Network * also has the Prius available for its members.

See also

References

External links

Toyota websites

Miscellaneous and news

Enthusiast sites

Toyota vehicles | Hybrid vehicles | Front wheel drive vehicles

Toyota Prius | Toyota Prius | Toyota Prius | Toyota Prius | Toyota Prius | Toyota Prius | Toyota Prius | Toyota Prius | トヨタ・プリウス | Toyota Prius | Toyota Prius | Toyota Prius

 

This article is licensed under the GNU Free Documentation License. It uses material from the "Toyota Prius".

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