First Drive: 2012 Buick LaCrosse eAssist [Review]

With its last vestige of "old man" Buick - the venerable Lucerne - now out of production, Buick's transformation is almost compete. Having seen good success with its LaCrosse flagship, it was only a matter of time before it too became "new and improved" for a second round of updates. That improvement shows up in the form of the 2012 Buick LaCrosse eAssist, a nerdy name for what amounts to big gains in mpgs and power, two things we'll gladly take.

To make the transformation, Buick has twisted around the LaCrosse lineup. A range-topping 3.6-liter V6 remains, but the 2.4-liter Ecotec four-cylinder gains some hybrid tech that General Motors seems happier rebranding as eAssist. Gone is the plain-jane 2.4, a motor that netted an impressive 30 mpg in the LaCrosse but somehow seemed out of sync with the large premium sedan crowd, a segment that includes such hotrods as the Chrysler 300.

But with the LaCrosse eAssist, Buick squares off against the Lincoln MKZ Hybrid and the Lexus HS 250h, two greenie luxo-rigs that currently make up the tiny premium hybrid market.


Future shock
GM's eAssist system uses power stored in an air-cooled lithium-ion battery for efficient engine and transmission functions under a variety of circumstances. Comprised of a 115-volt battery pack and a motor generator unit, it manages to boost fuel economy through regenerative braking and auxiliary power production when encountering heavier loads such as entering a highway or driving up mountain grades.

In true hybrid form, a motor generator unit takes over when the gas engine shuts off at stop lights. Most drivers won't even realize that the gas engine has turned off. Unlike other hybrids, however, the battery system is designed to provide power assistance to the internal combustion engine and not to store energy for an EV mode.

The part that GM engineers are especially chuffed about is that the eAssist's physical size allows it to be used in a variety of vehicles including an upcoming Buick Regal, and the soon-to-be-launched new Chevrolet Malibu. Made up of a battery pack, integrated power inverter, and a 12-volt power supply, it weighs only 65 lbs. and essentially straddles the rear axle, offering more trunk space than the average hybrid vehicle.

It's smooth down there
From the upside, the LaCrosse looks like the current model, except for some minor up-dressing. In the lower grille works are active shutters, which close off access to the vehicle's underside, routing air around the corners as seen in the Chevrolet Cruze Eco and the Ford Focus SFE.

Further on, down under, plastic and fiberglass-reinforced panels cause the air to slipstream by to minimize drag and undercar turbulence. GM officials claim that through their efforts at reducing vehicle weight on the eAssist LaCrosse, the total weight after the addition of the electrical system is virtually a wash when compared to the non-eAssist version.

The interior of the LaCrosse eAssist is similarly configured to its petrol-burning sibling aside from the addition of Eco-mode lights and battery status indicators in the gauge binnacle. On navigation-equipped models, a larger more descriptive readout is at hand. Non-navi models feature an LCD display between the speedometer and tachometer, which also displays turn-by-turn directions from OnStar.

Various trim colors are available. We like the charcoal interior as well as the brown and beige two-tone with faux wood trim across the dashboard. As dusk settles into night, a cool-blue light bar offers accent illumination along the dash and doors of the interior cabin, the same as you'll find in the gas LaCrosse.

Seating is comfortable throughout the cabin, although we struggled to get comfortable when we first got in, although we emerged from a lengthy drive quite satisfied. Like the standard LaCrosse, rear seat room is about as good as it gets.

The trunk space is also more than acceptable considering there is a battery pack in the rear. The added benefit is the rear seats still manage to fold forward for added cargo capacity, unlike most hybrids.

New age motivation
The LaCrosse eAssist's powertrain essentially yields a series of win-wins across the board: Fuel economy and power both go up.

By itself, the Ecotec is good for 182 horsepower and 172 lb-ft. of torque. Add the eAssist belt-driven, and liquid-cooled Lithium-ion battery and the motor generating unit for 15 more ponies and an impressive79 more lb-ft. of torque. With an overall curb weight of 3,835 lbs., The General says it goes from 0-60 mph in about nine seconds. Perhaps more importantly, GM says that fuel economy should hit 25/36 mpg city/highway, a tick behind more complex hybrids but hugely impressive nonetheless for a big car.

An added feature of the eAssist is the "onboard jump-start" function. Through some button pushing functions, it can rescue a LaCrosse when its 12-volt starter battery fails. Buick officials state the eAssist's life expectancy is well beyond the 10-year, 150,000-mile warranty period.

Like the standard LaCrosse, eAssist models ride on a kit made up of MacPherson struts with coil-overs and twin-tube dampers with gas-charged valves. A hollow stabilizer bar completes the package up front while the rear is made up of a four-link setup. Steering is through an electrically variable rack and pinion setup that did not feel overly artificial in the least.

For a power-assisted car, the LaCrosse really does impress, especially with the surprising maneuverability inherent to this platform. We drove it back-to-back against the decidedly smaller HS 250h, but the big Buick was undoubtedly the more fun way to get around. While other hybrids have a rather tentative drive feel, almost as though they were running on low friction motorcycle tires, we felt the Buick was as close to a real car as we have driven.

We watched a cruising pack of oldsters with gold chains driving Corvettes along California 1, otherwise known as the Pacific Coast Highway. They would bottom out on their shocks when negotiating highway expansion joints and imperfections, while our Buick just soaked up the bumps. Buick noise suppression engineers should be very proud of the their work. The cabin is generally very quiet, and delivers very high quality noise, vibration and harshness suppression.

The Hydra-Matic transmission offered a slap-shift mode to allow you to row the gears yourself. What it did not offer was steering wheel-mounted paddle shift levers, which would have been a much more elegant (this is, after all, a Buick) solution. As it is, the console-mounted shift lever is located too far rearward for most users and causes elbow contact with the cupholder array.

As for fuel economy - we'll wait for a more extended evaluation to see if we can net the estimated 36 mpg on a highway trip.

Above all, the LaCrosse eAssist is designed to feel and drive like a premium car, not a hybrid. And that's exactly what it did.

Leftlane's bottom line
Buick and, by extension, General Motors, goes out on a limb with an assist package that offers more power, and more than a 25 percent increase in fuel economy.

That it becomes the standard operating system in their very-visible, and important Buick LaCrosse, speaks volumes. It's definitely a car we would seriously consider when lining up gas-sipping mid-size luxury cars since it offers most hybrid benefits with few hybrid compromises.

2012 Buick LaCrosse eAssist base price, $29,960.