Understanding the 2012 Buick LaCrosse with eAssist System V. V. Haldavnekar 2010/12/05 With the 2012 Buick LaCrosse General Motors (GM) introduced the second generation Belt Alternator Starter (BAS) system, officially known as the eAssist, at the 2010 Los Angeles Auto Show. GM claims that eAssist, which means "light electrification" helps the near 2 ton car achieve a 25 percent increase in the fuel economy compared to the fuel economy of the 2.4L, 4 cylinder/6-speed LaCrosse. GM