Buick has given the LaCrosse some big updates for 2018. The full-size sedan gets a new eAssist mild hybrid system to help save fuel, and V6 models get a new transmission.

The eAssist is GM's newest generation mild hybrid system. It uses a motor generator (MGU) in place of a traditional alternator. The MGU generates electrical power to keep the 0.45 kWh lithium-ion pack charged, but provides electrical assist to the gas engine when needed. The gas engine is a 2.5L four-cylinder. Power output and fuel economy figures haven't been revealed, but they have said that it will have an increase in torque of nine percent over the four-cylinder alone and 16 percent better city economy compared to the V6.

The eAssist system also allows for start/stop to turn off the engine while the vehicle is stopped. Buick has installed active shutters in the upper and lower grilles to help further save fuel. Buick said that the small size of the eAssist system is designed "to maintain the LaCrosse’s fold-down rear seat and ample trunk space."

The 3.6L V6 that was new for last year will still be available. The 310 hp engine is no longer the standard engine, except on the Premium trim level, but will be an option on select trim levels. The V6 gets a nine-speed transmission in place of the eight-speed automatic that came with the engine last year.

The 2018 Buick LaCrosse goes on sale this fall, with pricing information available closer to the on sale date.