2012 Buick LaCrosse — Up to 37-mpg Highway



In the car business, consumer expectations frame the eventual satisfaction with a product. General Motors experienced the downside of consumer disappointment with “mild hybrid” models, such as the Chevrolet Malibu and Saturn Vue.

The term “hybrid” carries with it significant expectations among consumers. Exceptional fuel economy is demanded, and if a hybrid is only the “mild” version that offers a slight bump in efficiency, disgruntled customers will not award it the coveted two thumbs up. That was the case with the mild hybrid models. They cost more than the conventional gas models, but didn’t deliver much in the way of the expected miraculous “hybrid”-grade fuel economy.

The old GM might have continued banging its head against the same wall, but the new GM recognized the need to recast this technology’s depiction. The new solution is to apply mild hybrid electric powertrain technology without significant fanfare. Instead, the new technology is named “eAssist,” which could well be technical support for gadgets from Best Buy, so there is no consumer expectation associated with the label.

Priced at $29,960, the company’s first eAssist-equipped model is the 2012 Buick LaCrosse, to be followed by the 2012 Regal. Rather than charging a premium for eAssist, this powertrain becomes the new base engine in the 2012 LaCrosse starting this summer, and it will offer not only 25 percent better fuel economy, but also better performance than the current four-cylinder base engine.

The EPA-rated numbers for the eAssist LaCrosse are 25 miles per gallon in the city and 37 mpg on the highway, which is pretty impressive for a five-seat mid-to-large size sedan. The hybrid system in this case is a belt-alternator system rather than an electric motor that is integrated into the transmission, as is the case with strong hybrids.

That means it is a glorified alternator running off a belt that can also act as an electric motor to pour power back into the engine from a 115-volt lithium ion battery pack. Why bother? Well, 37 mpg for starters — and better acceleration.

While the belt system is rated at only 15 horsepower, it kicks in an extra 79 lb.-ft. of torque, compared to 172 lb.-ft. for the gas engine alone. Significantly, the electric motor’s torque is produced at 1,000 rpm, when the gas engine is gutless, so the impact on low-speed acceleration is immediately noticeable.

eAssist gives both excellent fuel economy and excellent around-town drivability at zero additional cost because it is the base engine in the LaCrosse. It also avoids some of the other pitfalls of strong hybrids — weight and space consumption.


The small eAssist system adds only 65 pounds to the LaCrosse and does not interfere with the folding rear seats, as many other systems do, so the car’s utility isn’t compromised.
As carmakers scramble to eke out every possible mile-per-gallon to meet federal fuel efficiency requirements look for more innovative solutions like eAssist. GM’s eAssist will hopefully let customers discover a pleasant surprise. — Dan Carney, Motor Matters

Manufacturer photo: The 2012 Buick LaCrosse with eAssist is a new fuel-saving technology that increases fuel economy by 25 percent compared to the four-cylinder/six-speed powertrain in the 2011 LaCrosse. The eAssist technology provides class-leading highway fuel economy of 37 mpg, while maintaining the luxury, performance and value expected from Buick’s flagship sedan.
Copyright, AutoWriters Associates Inc., 2011

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