The 2012 Buick LaCrosse, redesigned in 2010, is helping to shed the image that only AARP card-carrying members purchase the tri-shield brand. The average age of Buick buyers has fallen in the last decade from the mid-70s to the late 50s. To help juice up this trend, and also appeal to entirely new buyers (read green and trendy), Buick is offering a green machine, the 2012 LaCrosse eAssist. It delivers an EPA estimated 25 city/37 highway and 29 combined. Those fuel economy numbers are up from 19/30/23 for the 2011 LaCrosse with the same four-cylinder engine.

Even though eAssist is similar in principle to the very mild belt-alternator-starter (BAS) hybrid system first used on the 2007 Saturn Vue Green Line and 2009 Chevrolet Malibu Hybrid, you won’t find the hybrid badge on the LaCrosse that adorned those earlier vehicles. General Motors is avoiding the H word this time around in part because the word has become synonymous with the Toyota Prius, and also to dodge previous complaints that this mild form of hybrid technology doesn’t deserve the hybrid name.

A BAS system – sometimes called stop-start hybrid and micro hybrid – is a relatively low-tech hybrid design. It is composed simply of an energy storage device, like a battery, and a beefed-up starter motor that can also act as a generator. It essentially shuts off the engine when the car stops, and quickly restarts it when the brake pedal is lifted. Depending on design, it can provide some electric assist to the engine at speed, but not all-electric operation.

Even though the LaCrosse eAssist is coming at a time when automakers are pushing toward greater degrees of electrification – and Honda for one is trying to engineer itself out of a mild hybrid approach that precludes plugging in – this lower cost type of hybrid technology deserves a place in the hybrid family. After all, a jump in fuel economy from 19/30 city/highway mpg to 25/37 mpg can yield a solid 30 percent gain in fuel economy.

What Is eAssist?

The eAssist moniker is quite descriptive. The system enhances fuel mileage by “assisting” the gasoline engine, either by shutting down the engine when the car comes to a stop or cutting off the fuel supply when cruising or decelerating. When the car comes to a stop, the motor-generator unit spins the engine, bringing it to a smooth stop and also properly positions the engine for a smooth restart. In like manner, when in fuel shut-off mode, the motor-generator continues spinning along with the engine to provide immediate and smooth take-off power when the driver presses the accelerator.

2012 Buick LaCrosse eAssist

This new BAS design has noteworthy fuel economy gains compared to the earlier system, but neither comes close to fuel mileage delivered by a “full hybrid” operation like those in the Toyota Prius and Ford Fusion Hybrid. However, eAssist is more complex and performs better than the “micro hybrid” stop-start systems deployed in the Porsche’s 2011 Cayenne and Panamera models, and coming to nearly every Ford model. Buick’s eAssist is closer in function and fuel economy to the “mild hybrid” systems used in the Honda Insight and BMW ActiveHybrid 7.

There’s been a lot of debate – mostly trash talk – about whether or not eAssist is a mild- or micro-hybrid, some comparing the LaCrosse and the now defunct Honda Accord Hybrid. The proof is in the pudding. The eAssist system doles out better fuel mileage with its estimated 25/37 in the LaCrosse versus 24/32 in the killed-off Accord. Guess that makes eAssist at least as good as that mild hybrid.

More Power, Less Fuel

eAssist has a 15-kw motor-generator that replaces the original 5-kw motor in the Vue and Malibu. It is mounted on the engine in place of the alternator, providing both motor assist and battery charging via a new belt-drive system connected to the engine’s crankshaft. A 115V air-cooled lithium-ion battery pack is a significant upgrade from the old 10 kw nickel-metal hydride battery array. The new batteries bolster the engine with approximately 11 kw (15 horsepower) of electric power assist during heavy acceleration and 15 kW of regenerative braking power. That compares with only 2 kw of power assist and 5 kw of regenerative power on the previous setup.

Under the LaCrosse hood, the new eAssist teams up with a 182-horsepower 2.4-liter direct injection four-cylinder engine that generates 172 pounds-feet of torque. The previous design also worked with a 2.4 -liter four, but horsepower was 172 for the Vue and 164 for the Malibu. Plus, the LaCrosse engine produces eight more pounds-feet of torque thanks to high-pressure direct fuel injection that replaced the less-efficient multi-port injection type. Additionally, the engine has an aggressive fuel shut-off during deceleration that provides added fuel savings.

2012 Buick LaCrosse eAssist

A new Hydra-Matic six-speed automatic transmission replaces the conventional four speed used previously. Higher final-drive gearing keeps engine revs lower at highway speeds, boosting mpg. An auxiliary electric-driven oil pump is added to the transmission, which keeps it primed and the fluid flowing when the engine shuts down at a stop. That keeps the transmission ready to perform when the driver accelerates. The engine and transmission are engineered to enable regenerative braking and battery charging during coasting and braking.

More Fuel Economy Tricks

To eek out even more fuel sipping mileage, engineers added a few tweaks to the LaCrosse not found on the Saturn Vue or Chevy Malibu. Aerodynamics are improved with underbody panels that smooth airflow and electronically controlled shutters in the lower grille close at higher speeds to push more air over the vehicle.

A smaller gas tank is used – 15.7 gallons versus 18.4 – which reduces the curb weight by limiting the amount of fuel, but the eAssist LaCrosse’s range is still greater than the 2011 model. The final touch is low-rolling resistant tires that are optimized for performance and fuel economy.

It’s the total package – the eAssist hybrid system and tweaks – that produce the excellent fuel mileage numbers.

Exterior And Interior

When the covers came off the 2010 LaCrosse, it was clear the exterior design was influenced by the Riviera concept coupe introduced at the 2007 Shanghai Auto Show. Not as dramatic as the Riviera, the LaCrosse’s coupe-like roofline contributes to an elegant, thoroughly modern design. With time honored details like Buick’s waterfall grille, classic portholes and signature “sweep spear” at the rear quarter panels, designers have artfully crafted a look that is tailored for the 21st century. And, since the LaCrosse will become a global vehicle, the vertical front fascia complies with European pedestrian safety regulations, standards that are expected to be adopted in the U.S.

2012 Buick LaCrosse eAssist

Slide behind the steering wheel and the late 1970s advertising theme “Wouldn’t you really rather have a Buick?” comes to mind. Styled in China, designers continued the elegant exterior lines inside. The interior exudes the kind of quality and refinement that buyers of luxury cars are used to. Materials are rich looking, everything fits perfectly and switchgear feels substantial and operates with a smooth deliberateness.

Large speedo and tachometer gauges are easy to read at a glance. An ECO gauge below the speedometer aids the driver to optimize fuel efficiency, while the driver-information center has a hybrid diagram that shows electric power flow and the battery’s state of charge.

Officially classified as a mid-size car, dimensionally the LaCrosse is closer to a large sedan. Up front, driver and passenger are cosseted in firm seats that are multi-hour comfortable with plenty of leg and shoulder room. Three rear seat passengers can enjoy more than 40 inches of legroom and, in case your passengers tend to be toddlers rather than adults, there are three pairs of rear seat LATCH anchors.

2012 Buick LaCrosse eAssist

While the 2012 LaCrosse’s cabin has more than generous space, the eAssist version takes a hit on cargo room. The battery is placed behind the rear seats, which reduces the trunk space from 13.3 cubic feet to 10.9. Also, the opening is on the small side making it somewhat difficult to load large items.

As for high-tech gear, the LaCrosse eAssist offers all the gizmos and gadgets expected in a luxury automobile. New for 2012 is Buick’s IntelliLink system as standard equipment. IntelliLink provides smart phone integration, allowing users to control their mobile device through the LaCrosse’s new 7- or 8-inch, full-color touch screen display radio. The system allows smart phone control via voice activation and steering wheel-mounted controls. It also enables streaming stereo audio from the phone through services like PANDORA and Stitcher SmartRadio.

Other goodies available range from a backseat dual-screen video entertainment system to a Harman Kardon surround-sound system as well as a navigation system, rearview camera and a blind-spot warning system.

On The Road

In the not-too-distant past, Buick’s floaty ride was a throwback to earlier times, and the handling and performance was far behind nearly all-modern sedans. Today, the 2012 LaCrosse eAssist is a more than capable performer and handles as well as any family sedan.

In daily life, our LaCrosse test driver was rock-solid and as comfortable as flannel pj’s. The seats are, indeed, splendid and the sedan managed our most rugged urban terrain with a dismissive sneer. Even the worst road hazards failed to produce kickback through the nicely weighted steering system and the shocks took the worst out of every bump and pothole. The cabin was serenely quiet with just a whisper of wind noise.

2012 Buick LaCrosse eAssist

We found the eAssist hybrid system faultless to the point that after a few miles it was easy to forgot about it. When the engine restarts after a stop sign pause, there are no shudders or electric motor noises. Response to throttle input is prompt, almost brisk, as torque assist from the motor joins the gasoline engine. It may not be sport sedan quick but we found freeway merging and passing slower vehicles were accomplished in short order.

The LaCrosse also came through with fuel economy. After a week of driving on city streets and a couple of runs on Interstates, the odometer had logged 359 miles with an average of 30.7 mpg, which was more than the EPA’s estimated 29 combined mpg. And in fairness, the final tally was affected by a 60 mile-plus Interstate stint with the speedometer pegged mostly at 80 mph.


In an unconventional move, Buick has positioned the LaCrosse eAssist as the base model. It starts at $29,995 and includes a power driver’s seat, dual-zone automatic climate control, a seven-speaker audio system, satellite radio, Bluetooth, USB connection, the IntelliLink system and GM’s OnStar.

Stepping up to the Convenience Group at $30,465 not only adds remote start, power lumbar and auto dimming mirror, it also offers the choice of a 3.6-liter V6 rated at 303 horsepower for the same price. While we haven’t driven a V6 LaCrosse, and I usually prefer more power, the V6’s fuel economy of 17/27/21 would sway me toward eAssist.

2012 Buick LaCrosse eAssist

Comparing the LaCrosse eAssist to rivals, it is less than Lincoln’s MKZ Hybrid starting at $34,755 and the Lexus HS 250h with a base price of $36,330. While both competitors have better in-town fuel economy than the Buick – 41 mpg for the Lincoln and 35 mpg for the Lexus – the LaCrosse on the highway nudges the MKZ by 1 mpg and the HS 250h by 3 mpg.

eAssist is another sign that hybrid technology – in all its variety of flavors – will become increasingly commonplace in the auto market. In fact, Buick has recently introduced the 2012 Regal eAssist, and the all-new 2013 Malibu Eco with eAssist is now arriving in dealer showrooms.

However simple the eAssist hybrid system is, it has impressive fuel economy gains and reduces emissions and, when paired with the Buick LaCrosse, there’s no additional cost.

Prices are Manufacturer Suggested Retail Price (MSRP) at time of publication and do not include destination charges, taxes or licensing.