Buick has announced a second eAssist vehicle for 2012, with this Regal joining the previously announced LaCrosse version. eAssist is essentially a (very) mild hybrid system, in that it can’t propel the car by itself. The Regal eAssist has a belt-driven, liquid-cooled electric motor/generator in place of the usual alternator; it kicks in with 15 hp (11 kW) and 79 lb-ft of assistance for the 2.4-liter four-cylinder engine during hard acceleration and when driving up steep grades. But the light kick in the pants is almost beside the point—saving fuel is the thing.
Buick says the system swells the car’s fuel economy to an impressive 26 mpg city and 37 highway; for comparison, the 2011 Regal posts EPA ratings of 18/30 with the same 2.4-liter four sans eAssist. It’s worth mentioning, though, that Buick attaches the same 37-mpg highway number to the bigger, heavier LaCrosse eAssist, which also is estimated to achieve 25 mpg city—just 1 fewer than the assisted Regal. Still, there aren’t many vehicles the size of either Buick that are as efficient, so we’ll take it.
The energy fueling the motor-generator is stored in a 0.5-kWh lithium-ion battery pack located in a compartment behind the rear seat, and is generated through regenerative braking and recapture during deceleration. The 65-pound battery pack eats into cargo capacity a bit, leeching 3.2 cubic feet from the non-eAssist Regal’s 14.3-cube trunk. One half of the rear seat still folds, though, preserving at least some of the practicality of the regular car.
The eAssist is a regular Regal in nearly every other regard. There are no sheetmetal changes that accompany the optional system—it's standard on 2.4-liter LaCrosses—and the interior is largely identical save for some eco-minded instrumentation and driver-coaching readouts. There also are lighter 17-inch wheels wrapped in low-rolling-resistance rubber and some aerodynamic tweaks performed to the underbody.
As mentioned, the eAssist has the same 182-hp, 172-lb-ft direct-injection 2.4-liter as the base model (a 2.0-liter turbo four is optional in other Regals, but not the eAssist), and it also carries over the six-speed Hydra-Matic automatic transmission found in other 2.4-liter models, albeit with some internal tweaks and revised gearing. Like more robust hybrids, this car has an engine stop/start system and fuel cut-off during deceleration.
We haven’t yet driven any eAssist vehicles, but we weren’t enamored of a similar system (that used nickel-metal hydride batteries) that was installed a few years ago in the Chevrolet Malibu, Saturn Aura, and Saturn Vue. But this is the de facto next generation of that system, and the efficiency gains are much more impressive here—we look forward to evaluating the system’s overall evolution.
Thanks to: Car and Driver
