Buick is revising its LaCrosse luxury sedan again in 2012. While still offering a choice of either a 4-cylinder or V6 engine, both have undergone changes to improve fuel economy and increase power. The biggest news comes for the 4-cylinder engine, which is now equipped with eAssist. This “light electrification” technology transforms the 4-cylinder powertrain into a mild hybrid, designed to give the internal combustion engine (an Ecotec direct-injection 2.4-liter DOHC inline 4) a boost of power for stressful driving situations (e.g., hard acceleration or hill climbing). Although the LaCrosse will not run exclusively on electric power, the air-cooled lithium-ion battery will deliver up to 15 extra horses to the gasoline engine’s 182 hp combined with 172 lb-ft of torque. The battery, charged via regenerative braking, is located between the rear seat and trunk, reducing available trunk space to 10.9 cubic feet, but still allowing for a split-folding rear seat. The system is matched with a new 6-speed automatic transmission designed to work with the electric power.

The fuel economy gains with eAssist are noticeable, with a 32% increase in city fuel economy (now 25 mpg) and a 20% increase in highway fuel economy (now 36 mpg) according to Buick. Fuel savings are also improved via a start-stop system that shuts off fuel delivery during deceleration. At highway speeds, fuel economy is also boosted with a new active shutter system in the car’s lower grille. The shutter opens or closes depending on the engine coolant's temperature and speed, closing when the engine needs less cooling (e.g., at highway speeds) and opening when there is a greater risk of engine overheating (e.g., traveling up a grade, towing a trailer or in summer city driving conditions). When closed, the aerodynamics of the car improve, as air is directed around the front and down the sides of the sedan, rather than through the shutters. Four underbody panels (covering about half of the sedan’s nether regions) and 17-inch wheels with low-rolling-resistance tires have also been added as standard features to improve fuel economy.

The new LaCrosse with eAssist will start with a price tag of $29,960 (with an additional $860 destination charge). Buick sees the Acura TL, Lincoln MKZ and Lexus ES 350 as its sedan’s key competitors, but notes that the LaCrosse I4 with eAssist bests its rivals in both city and highway fuel economy. The 2012 eAssist LaCrosse also matches or surpasses the highway numbers for hybrid contenders such as the Lexus HS hybrid, Lincoln MKZ hybrid, Infinity M hybrid and Toyota Camry hybrid.

Buick has announced that later versions of the 2012 LaCrosse with eAssist will also be equipped with standard Buick IntelliLink to connect a smartphone (via Bluetooth or USB) to a new 8-inch touchscreen display radio, allowing for smartphone control via voice activation and steering-wheel-mounted controls. In fact, Buick seems determined to convince consumers that the new LaCrosse will not compromise the ride, comfort, quiet or luxury of Buicks of old. A 4-wheel independent suspension system, standard StabiliTrak electronic stability control, front and rear disc brakes with antilock braking, electronic brakeforce distribution and brake assist all continue as standard features. Traction control, airbags (including front-, side- and roof-mounted head-curtain) and a year of OnStar service supplement safety in the LaCrosse. Standard variable-effort power steering gives greater assistance at lower speeds when it is harder to steer the vehicle, but offers less assistance at faster speeds, increasing road feel and stability. The LaCrosse interior features chrome and woodgrain styling highlighted by what Buick calls “ice blue” ambient lighting throughout the cabin and instrument panel, and the brand’s QuietTuning continues to muffle noise in the cabin. Available technology will include a hard-drive navigation system with 10 of the car's 40GB saved for music storage. Bluetooth, an auxiliary audio jack and a USB port will also be available. In addition, buyers can opt for Blind Zone Alert technology (notifying the driver when a vehicle is approaching in a blind spot) as well as a rear-view camera displaying its image in the navigation system screen. In the second row, passengers can enjoy an optional power rear sunshade and an available DVD entertainment system with screens integrated into the backs of the front seats.

Most anticipate that Buick will do away with last year’s trims (the CX, CXL and CXS), and instead offer trims defined by packages of available options (likely a base, Convenience, Leather, Premium and Touring trims). The LaCrosse’s other engine option will be available at no extra cost for some of these trims (not yet specified by Buick). Despite Buick’s excitement over the standard 4-cylinder with eAssist, it has not neglected its V6 for 2012. The direct-injection 3.6-liter V6 with variable valve timing can use E85 fuel and improves its horsepower by 23 (up to 303 hp) while producing 264 lb-ft of torque. Despite the increase in power, the V6 LaCrosse maintains its 2011 fuel economy numbers (17 mpg city/27 highway). Buick achieves this in several ways, including a lighter-weight aluminum alloy V6 with a new cylinder head design. Larger intake valves stay open longer for more air and greater combustion, and the revised fuel system offers a new fuel pump and fuel rail. New standard V6 LaCrosse features will likely include dual-zone climate control, a driver information center, Bluetooth and a USB port, as well as 17-inch wheels. While front-wheel drive will continue to be standard, Buick also expects to produce an all-wheel-drive version of the V6, as it did in 2011.