Buick unveiled its eAssist mild hybrid technology on the 2012 LaCrosse at the Los Angeles Auto Show last year. Now, the company will unveil a similar system for the smaller, hot-selling Regal sedan.
If you're thinking that eAssist is Buick's answer to full-hybrid systems from Infiniti, BMW, Mercedes-Benz and Lexus, think again. Even Buick only refers to its system as a hybrid in passing, preferring to refer to eAssist as "light electrification."
While eAssist is the base drivetrain in all LaCrosse models, it's an optional drivetrain in the Regal, slotting above the base model, but below the turbo.
Like the system in the LaCrosse, the Regal's eAssist uses a small 15-kilowatt motor/generator mounted on the block of the 182-hp 2.4-liter Ecotec four-cylinder engine. It's connected to the engine through a belt drive system. Unable to move the car on its own, it instead lets the engine shut down during coasting maneuvers and at a stop.
The motor uses a 0.5-kilowatt-hour lithium-ion battery pack in the trunk to restart the Regal, and it also keeps the engine spinning when the fuel is switched off during coasting so that the car doesn't bog down suddenly.
The six-speed automatic has also been redesigned and reprogrammed to integrate more smoothly with the on-again, off-again engine. The assist from the electric motor means that the gearing can be taller, which helps highway fuel efficiency. The clutches have also been reworked, and the transmission now has an electrically driven pump to keep it primed when the engine is off.
Right now, Buick is claiming that it will improve the Regal's fuel economy up to 25 percent, from its current 19 city/30 highway to 26 city and 37 highway. That's not world beating, but it's pretty darn good for a premium sedan that still has about 200 net horsepower. It's also better than its closest competitor, the Acura TSX, by a healthy margin.