eAssist light electrification becomes the standard propulsion system for Lacrosse in 2018, and supports a GM-estimated 25 mpg city and 35 mpg highway. The new eAssist light electrification propulsion system combines a compact electric motor and advanced 24-cell air-cooled lithium-ion battery pack with a 2.5-liter 4-cylinder gas engine and six-speed automatic transmission. The Motor Generator Unit replaces the traditional alternator. Electric assist provides a power boost for an extremely smooth launch from the Auto-Stop mode and additional torque to the engine, when needed, to optimize overall driving performance and efficiency. Regenerative braking stores some of the energy normally lost during braking or coasting in the lithium-ion battery pack. A nine-speed automatic transmission is paired with the available 3.6-liter V6.
