Jul

General Motors Picks A Bigger Engine For The Volt

Posted by admin Published in Chevrolet

The engineers busting their humps to get the Chevrolet Volt built by the end of 2010 can check another item off their to-do list now that they’ve picked an engine, er, range-extender, to put under the hood.

General Motors says the Volt will come with a 1.4-liter normally aspirated four-cylinder engine from the Family 0 line of engines it uses in Europe and plans to put in the forthcoming Chevrolet Cruze. When the Volt was unveiled at the Detroit Auto Show about 18 months ago, the plan called for a 1.0-liter turbocharged three-cylinder, but The General says four is better than three.

First, it’s worth repeating that the engine will not drive the Volt’s wheels at any duration. It’s essentially a generator to charge the car’s 16 kWh lithium-ion battery on the fly as it approaches depletion. Hence the term “range extender.”

“The objective is to keep the engine off and when the engine comes on, you don’t want to know that it’s on,” Larry Nitz, director of hybrid powertrain engineering, told Green Fuels Forecast. “You want it really smooth and a four cylinder

is smoother than a three.”

Nitz says the four-banger offers better brake-specific fuel consumption - in lay terms, it’s more efficient - than the three in steady-state operation such as charging a battery. It’s lighter, too, when you consider the weight of the turbocharger and associated plumbing it would require. And it’s cheaper - a big consideration for GM as it tries to keep the Volt’s sticker price below $40,000.

That’s all well and good from an engineering and accounting perspective, but is a 1.4-liter engine big sufficient? Absolutely, Nitz says. The engine will produce about 50 kW (roughly 67 horsepower), half as much as the electric drivetrain. That’s more than sufficient to charge the battery while providing suitable juice to keep the electric motor turning, Nitz says.

“Zero to 60, passing maneuvers, you’ll be fine,” he says. “The ability to actually use more than about 50 kW doesn’t exist very frequently.”

Photo by GM.

Original post by Chuck Squatriglia