GM's eAssist: Just don't call it a hybrid

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Hybrid is a word you won't hear uttered with much reverence around the halls of General Motors.

The company's beef is with the full-hybrid systems in cars like Toyota's Prius.

What GM appears to like least about full-hybrid technology is its large price tag.

In cars like Prius, a hybrid system uses electricity generated by a gasoline engine to charge a battery pack. That battery then fuels an electric motor that can propel the car for short distances at low speeds, or work in tandem with the gasoline engine to provide extra boosts of power when needed.

GM has developed what it believes is a more cost-effective and efficient alternative.

Called eAssist, this system's electric motor can't power the wheels on its own. What it does do is provide added boost -- about 15 horsepower -- to the 2.4-liter four-cylinder Ecotec engine during heavy acceleration and when climbing grades.

Combined output of the motor and engine is 182 horsepower.

The eAssist system primarily uses energy captured during braking to charge the lithium-ion battery.

Another eAssist gimmick is automatic stop-start that shuts off the gasoline engine when the car is stopped and then starts it when the driver reengages the accelerator.

In certain instances it also cuts fuel to the engine when the car is decelerating.

If you must use the term hybrid when referring to GM's new system, its engineers grudgingly acknowledge that mild hybrid isn't without some merit, but you won't hear them say it.

A first application of eAssist will be in the 2012 Buick LaCrosse. It will replace the four-cylinder gasoline engine currently available.

Fuel economy of the eAssist-equipped LaCrosse, as estimated by the EPA, will be 25 mpg in the city and 36 mpg on the highway.

This is notably better than the 17 mpg city and 27 mpg highway for the 2012 LaCrosse's 303-horsepower V6, as well as the 19 mpg city/30 mpg highway of its current four-banger.

Buick wants to provide customers a no-extra-cost choice between the high fuel economy of the eAssist and the performance of the V6.

Regardless of which powerplant the customer chooses, price and standard equipment are identical.

The suggested retail price of similarly equipped trim levels will be the same no matter the power delivery system.

Expect to see eAssist offered in other GM models, such as the 2012 Buick Regal and the 2013 Chevrolet Malibu.

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