POWER PLAY; Chevy Volt's E-flex powertrain tops our list.(News)

Byline: BOB GRITZINGER

If there's a "Wow, did you see that?'' at this year's North American International Auto Show, it is most likely the Chevrolet Volt.

How, out of some four dozen world debuts, does this unremarkable-looking General Motors concept rate so highly in our estimation? Consider a few facts:

* Volt can deliver 40 to 45 city miles of pure electric driving, allowing commuters who live within 20 miles of work to never burn any gasoline, instead relying on a daily plug-in recharge from a home or office 110-volt outlet.

* When driving beyond the electric-only range, the car's turbocharged 1.0-liter three-cylinder engine will automatically start, spin a generator and recharge the battery, effectively providing 50 mpg and a city range of some 640 miles from a 12-gallon tank of unleaded fuel.

* Running on E85, with only 15 percent gasoline in each 85 percent ethanol-based gallon of fuel, Volt hits an astonishing 525 miles per gallon of actual gasoline in the mix.

* The Volt concept shown at Detroit is equipped with an internal combustion engine that runs on regular unleaded gasoline, but GM's E-flex System is engineered to accept any powertrain from fuel cell to biodiesel to 100 percent ethanol to hydrogen internal combustion engine, depending on the available fuel in that part of the world.