2012 Buick LaCrosse With eAssist Preview

Better FE through eAssist, an upgraded BAS Start/Stop System. 2012 Buick LaCrosse w/ eAssist ? Rated (calibrated for) 37 mpgUS highway and $29,960 to start. While the 2012 Buick LaCrosse with eAssist is touted to deliver 25 percent better highway fuel economy than the current LaCrosse, during a colder country road drive, it proved to provide middling results.