What is it? It may not be much of a hybrid, but for 2012 the Buick LaCrosse will come standard with a mild-hybrid drivetrain. A development of the belt-alternator-starter hybrid system that last appeared in the slow-selling Chevrolet Malibu Hybrid, the LaCrosse eAssist system is good for 37 mpg on the highway, according to General Motors.
The belt-alternator-starter (BAS) hybrid system is mated to GM's 2.4-liter Ecotec four-cylinder engine and a new-for-the-mild-hybrid six-speed automatic transmission. The hybrid drivetrain uses a new 115-volt lithium-ion battery, that weighs 65 pounds and still allows half of the rear seat to fold down to carry larger cargo. The new electric motor/starter cranks out 15 hp, which GM says is three times the hp available in the Malibu's BAS system. The hybrid system shuts down the engine at stops and recaptures energy from the car's momentum when stopping to boost fuel economy. GM claims there will be no price premium for the hybrid system.
GM claims the system will boost fuel economy by 24 percent, compared with the four-cylinder 2011 LaCrosse. In our testing that four-cylinder LaCrosse already returned 37 mpg on the highway, and 15 mpg in the city, for an overall average of 23 mpg.
When will it be available? Summer 2011.