Toyota Prius (2001)
SEE ALSO: Toyota Buyer's Guide
by Carey Russ
Welcome to the 21st Century. Ever-higher fuel costs and increasing demands for cleaner air are expected to change the cars we drive. One of the first steps will be hybrid drivetrains, power systems that combine an internal combustion engine with an electric motor for increased fuel economy and lower exhaust emissions. Actually, hybrid cars are here now. The 2001 Prius is Toyota's entry into the field. The Prius has been available in Japan since 1997, and test versions have been in the U.S. for the past few years as well. The "official" American-spec Prius is slightly more powerful than the Japanese version to better deal with the higher speeds and longer distances of American driving. A Prius has been my transportation for the past week, and it has been a very interesting week.
The Prius is most remarkable for being unremarkable. It is a true five-passenger sedan, with slightly more interior space than a Toyota Corolla. Its complex hybrid gasoline-electric drivetrain is no drawback. With one minor exception, regenerative braking, the Prius drives like any other small sedan. Its batteries are recharged by the gasoline engine and by regenerative braking - there is no need to plug it into a recharger like a pure electric car. It can go over well 400 miles on an 11-gallon tank of regular unleaded gasoline.
With any vehicle, fuel economy is dependent on operating conditions. But the Prius seems especially sensitive to driving style and traffic conditions. Even more than a normal gasoline-powered car, it thrives when driven gently. That's when it runs, very quietly, on electric power. In a mostly-downhill, light-throttle stretch of mixed highway and secondary road driving, I saw a 94 mpg average. In full-on / full-stop city traffic, in 90-degree temperatures with the air conditioning and CD player going, it was a less- impressive 33 mpg. Turning the accessories off and driving more gently in the same situation saw 46 mpg. My average, driving normally, was around 43 mpg. This compares with 30 mpg for the last Corolla I tested, and 31 for the ECHO sedan. There have been cars rated at or above the Prius's real-world mileage, but they are smaller and far less comfortable. The Prius is an important step toward the future, and, more importantly, it's a real car for everyday use.
APPEARANCE: The Prius certainly looks futuristic, with its angular styling, steeply-sloped hood, large passenger cabin, and short overhangs. It is similar to Toyota's ECHO, but slightly larger and sleeker. Its tall, short shape makes maximum use of a minimum footprint.
COMFORT: All of the comforts expected in a contemporary sedan are found as standard equipment in the Prius. This includes air conditioning, an AM/FM/cassette stereo with optional CD player, power windows and mirrors, and remote keyless entry. The interior styling is as unusual as the exterior, but is quite logical. The main instruments are placed in the center of the instrument panel at the base of the windshield. This requires less eye refocusing than the usual, close position. The Prius has cloth upholstery and the usual excellent Toyota fit and finish. Two adults can fit comfortably in the rear seat, with room for a third, smaller person between. The trunk- mounted battery pack is small enough to have minimal impact on trunk space.
SAFETY: The Prius has safety cage chassis construction with front and rear crumple zones and side impact protection. The seats are designed to reduce the chance of whiplash injury, and all seating positions have three-point safety belts. Dual front airbags can be assisted by optional side airbags, and antilock brakes are standard.
ROADABILITY: In its ride and handling qualities, the Prius is little different from any other small sedan. It's no sports car, but fulfills its mission of urban transportation well. The electrically-assisted power steering is very light, and its 31-foot turning circle makes parking and low-speed maneuvering easy. The hybrid drivetrain is most noticeable by what's missed - noise. In most conditions, the Prius is as quiet as one of its upscale Lexus cousins, and sometimes even quieter. It's far quieter and smoother than any other small, inexpensive sedan.
PERFORMANCE: The Prius's hybrid drive system consists of a 1.5-liter gasoline engine, a permanent magnet AC electric motor, a 274-volt nickel-metal hydride (Ni-MH) battery pack, an AC generator, and electronic controls that enable the various parts to work together. The lightweight, low-friction engine develops 70 hp at 4,500 rpm, with 82 lb-ft of torque at 4,200 rpm. The electric motor makes 44 horsepower between 1050 and 5600 rpm, with 258 lb-ft of torque from 0 to 400 rpm - as much torque as many 3.0-liter engines, but right from a standstill, when it's most needed. When starting or moving under low load conditions the gas engine is turned off and the car runs under electric-battery power. In normal operation, the gas engine runs, and its power is split through a planetary gearbox that directs it to both the front wheels and the generator, which generates electricity to run the electric motor, aiding the engine power, or to charge the batteries. Under hard acceleration, extra energy is drawn from the battery pack for more power. When slowing or descending grades, the electric motor operates as a generator for regenerative braking, slowing the car and charging the batteries. At a stop, the engine turns off unless high demands are placed on the system. For the most part, the system operates transparently. Because there is no conventional transmission, acceleration is very smooth, with no gear shifting. Under flat-out acceleration, some engine noise is heard, and the car feels like a small-displacement car with an automatic transmission that hasn't locked up. The only way to tell whether the car is operating under gas, electric, or combination power is by looking at the monitor in the center of the instrument panel. Most of the time it is very difficult to tell when it changes from pure electric to gas- electric. The shift controls are simple: Park, Reverse, Neutral, Drive, and Braking. Most positions are self-explanatory; the last is used for extra regenerative braking when descending long grades. And that does make a difference, adding extra stopping power to the Prius's already good antilock disc/drum system.
CONCLUSIONS: If the Toyota Prius points to the automotive future, the future looks good.
SPECIFICATIONS 2001 Toyota Prius Base Price $ 19,995 Price As Tested $ 20,855 Power Specification parallel/series gasoline-electric hybrid system with 1.5-liter twincam inline 4-cylinder gasoline engine and permanent magnet AC electric traction motor, 274 volt Ni-MH battery pack Horsepower engine: 70 @ 4500 rpm ; motor: 44 @ 1050 - 5600 rpm Torque (lb-ft) engine: 82 @ 4200 rpm ; motor: 258 @ 0 - 400 rpm Transmission electronically-controlled continuously variable transmission (ECVT) Wheelbase / Length 100.4 in. / 169.6 in. Curb Weight 2,765 lbs. Pounds Per Horsepower 24 Fuel Capacity 11.9 gal. Fuel Requirement regular unleaded gasoline, 87 octane Tires P175/65 SR14 Bridgestone Potenza RE92 Brakes, front/rear vented disc / drum with antilock, regenerative braking from traction motor Suspension, front/rear independent MacPherson strut / torsion beam axle Drivetrain front engine, front-wheel drive PERFORMANCE EPA Fuel Economy - miles per gallon city / highway / observed 52 / 45 / 43 0 to 60 mph 12.7 sec 1/4 mile (E.T.) 19.2 sec Coefficient of Drag (cd) 0.29 OPTIONS AND CHARGES Carpet floor mats $ 70 CD player $ 335 Destination charge $ 455