Prior to the 2018 model year, the Buick Lacrosse featured just one engine -- a gas V6. For this new model year, it gains a smaller engine that packs some light electrification.
The base engine offering in the 2018is now a mild hybrid. The 2.5-liter I4 is connected to an electric motor and a lithium-ion battery pack, offering both additional performance and higher fuel economy.
The electric motor replaces the alternator, and it acts as both a motor and generator. It can send additional torque to the wheels for a sportier start, or it can act as a generator under braking, capturing energy to refill the 86-volt lithium ion battery. The battery will also power the vehicle when it turns off as part of the stop-start system.
Compared to previous iterations of Buick's eAssist mild hybrid setup, this new version offers 9 percent more torque. The battery is also more compact than before, in an effort to keep trunk space ample and maintain the LaCrosse's fold-down rear seat, both of which are occasionally reduced or removed when hybrid systems are incorporated -- the battery's got to fit somewhere, after all.
The 2017 LaCrosse, with its 310-horsepower V6, was rated at 21 mpg city and 31 mpg highway with front-wheel drive. Buick claims the eAssist system will improve city fuel economy by 19 percent, which would bump it up to 24 or 25 mpg city, but EPA numbers are not yet out for the 2018 model year.
When it goes on sale in the fall, the 2.5-liter eAssist setup will become the new base engine for the 2018 LaCrosse -- worry not, fans of gasoline, as the V6 is still available. While hybridization might seem more expensive, given its additional complication, it actually brings the base price of a 2018 LaCrosse down to $30,490, from 2017's starting price of $32,065. There's no word yet on pricing for the V6 model.