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The Toyota Prius is one of world's first commercially mass-produced hybrid automobiless. Manufactured by Toyota, the Prius first went on sale in Japan in 1997. Since then, there have been over 120,000 units sold in Japan, Europe, and North America as of September, 2003. The Prius (2000~2003 model years) is certified as a super ultra low emission vehicle (SULEV) by the California Air Resources Board (CARB).
The Prius has been called a true hybrid vehicle, designed from the bottom up. Toyota's goal for the Prius is to reduce the amount of emissions it produces and to be as energy-efficient as possible. They used several methods to try to achieve this goal, including:
The engine is permitted to shut down once the engine has warmed up and the catalytic converter in the exhaust system has reached operating temperature. Once this occurs, the Prius can be driven on electric power only; this is sometimes referred to as "stealth mode". This further reduces gasoline consumption and wear and tear on the engine. When driving conditions demand additional power from the engine, it is designed to start up automatically.
Frequent starting up and shutting down of the engine should not cause additional wear and tear, as in conventional automobiles, because the drive motors have enough power to quickly and smoothly spin the engine to optimal RPMs (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.
The Prius gets higher gasoline mileage in the city because the batteries get used more, whereas on the highway, the engine is used in order to recharge the batteries, and the wind resistance is higher.
How it works
Touted advantages of the Prius over previous energy-efficient designs include never needing to be plugged in, all power being delivered ultimately from the gasoline engine. This means it drives like a traditional ICE automobile, the onboard computer in the Prius taking care of shifting power to and from the engine and motors, automatically determining the most efficient use of the engine or the electric motors (or both) based on driving conditions, and when to charge the battery.2004 Prius
The Prius 2004 model year is a complete redesign of the previous generations of Prius. With a new drag coefficient of 0.26 and featuring the third generation hybrid powertrain technology called Hybrid Synergy Drive (HSD), the new 2004 Prius has more room (4 doors plus a rear hatch, a smaller but more powerful NiMH battery), is more powerful (2 seconds faster in 0 km/h to 96 km/h acceleration) and 15% more fuel efficient than the previous generation Prius (59 mpg city, 51 mpg highway, according to the EPA), when driven properly[1], yet is still 90% cleaner than conventional gasoline-only automobiles. It comes with an Advanced Technology Partial Zero Emission Vehicle (AT-PZEV) certification by CARB. As an interesting side note, a $2,200 option package offered in Japan for the 2004 model gives it the ability to park itself. 80% of the Prius buyers have chosen this option. The system is not intelligent, though, so it is very limited.[1]Notable facts
Other hybrid-engine vehicles
See also
External links
