2011 Automobile of the Year: Chevrolet Volt

With a full charge in its 16-kWh lithium-ion battery pack, the Volt delivers 25 to 50 miles of electric driving before firing up a combustion engine for another 300 miles of range fueled by premium gasoline. That engine, the range extender, primarily spins a generator to feed electricity to the motor driving the wheels. It is also capable of providing relatively small amounts of torque to the wheels in parallel with the electric drive motor. The Volt's powertrain hardware isn't exceptional, though. After all, Toyota has sold nearly two million Prius hybrids in the last thirteen years packing two electric motor/generators and a small gas engine under the hood, just like the Volt does. Instead, the intangibles set the Volt apart: control strategies, calibration, computer code, and the philosophy behind it all. Using a planetary gearset and three clutches to connect the two motors and the engine, the Volt powers the wheels in five distinct operating modes. To the driver, though, the Volt has only one mode: effortless. Although classifying the Volt as a hybrid or an extended-range electric is a matter of semantics, it is unquestionably an electric car from the driver's seat. It launches with whisper-quiet, high-pitched whirs, which are exchanged for the subtle din of wind noise as it reaches speed. A power output of 149 hp won't impress anyone, but 273 lb-ft of torque and a responsive right pedal make it more lively than your typical compact car. Electric propulsion also redefines powertrain refinement. There is no nudge from a transmission swapping cogs or the CVT-induced drone of a strained engine. Power delivery is fluid, acceleration is smooth, and cruising is nearly silent. GM's official line on range -- formerly said to be 40 miles of electric driving -- is now hedged as "25 to 50 miles," due to the profound effect that driving style, exterior temperature, and accessory use have on range. On a suburban route with typical traffic and driving behavior, we covered 40.8 miles in pure electric mode.