2007 Toyota Prius

Toyota's Hybrid Synergy Drive system, considered a "full hybrid" layout, consists of a 1.5-liter four-cylinder Atkinson-cycle gasoline engine that generates 76 horsepower, coupled with an electric drive motor. The electric motor produces 50 kilowatts, for combined gas-engine/electric output of 110 horsepower. Capable of running for short distances on electricity alone, the Prius switches automatically and almost seamlessly between the two power sources. When stopped or coasting, the gas engine may shut off to conserve fuel. Regenerative braking, while coasting, helps keep the batteries fully charged.


Like other continuously variable transmissions, Toyota's planetary gear-type CVT has no conventional fixed gear ratios. Instead, it provides infinitely variable ratios in accord with changing driving conditions. Both the throttle and the shift control are operated electronically "by wire," and the transmission is governed by a short dashboard-mounted lever. Power distribution from the hybrid powertrain may be viewed on the standard seven-inch display monitor. If a navigation system is installed, the video screen can also display map and journey information.

Performance

As Toyota says, the Prius looks like no other car on the road today. It's also more aerodynamic than most production vehicles. A low (0.26) coefficient of drag lets the Prius slip through the air more readily than most cars, which helps boost gas mileage and may also decrease interior noise. Vehicle Stability Control is an option, which helps keep the car on course by detecting and correcting wheel slide during cornering. A backup camera also is available.


Thrilling isn't quite the word, but the Prius can be fun to drive—at least some of the time. Performance is acceptable but modest, in keeping with Toyota's claim of 0-60 mph acceleration in about 10 seconds. Quicker than Honda's Civic Hybrid, a Prius accelerates eagerly at low or midrange speeds, if less so at higher velocities. Oddly, despite the gearless CVT, you may feel a "gear change" as the Prius reaches speed.


Ride comfort is a plus, at least on relatively smooth surfaces, and rough spots are largely subdued. Though you can hear the engine, especially while accelerating, the Prius is especially quiet. The regenerative braking may produce a slight jolt when approaching a stop, but it's not especially bothersome. Visibility to the rear is hampered by the thick horizontal bar across the back window. Rear-seat headroom is marginal, though leg space is ample. Some controls may confuse the uninitiated.