( http://www.TFLcar.com )  Mechanically speaking, the 2012 Buick LaCrosse eAssit is a hybrid of a hybrid. A full hybrid, like Toyota's Prius, or hybrid competitors to the Buick like Lincoln's MKZ and Lexus's HS 250h, can run on battery power alone during some urban driving. Not the LaCrosse. In terms of preserving the planet, Buick's simplified hybrid system essentially works to shut off the engine when the car stops (like at a stoplight) and when the vehicle is decelerating or coasting. Check out this first drive review of the 2012 Buick Lacrosse eAssist.