GM walked away from mild hybrids after Saturn was sent to the company's scrap heap. At the time, both the Chevrolet Malibu and the Saturn Vue wore the tech, but with the Vue out of the picture, the company couldn't justify the cost of investing in the drivetrains. Unlike a full hybrid, mild-hybrid vehicles can't cruise along on just electric power. Instead, the system allows the gasoline engine to shut off when the vehicle is stopped. The electric motor then starts the engine again when the accelerator pedal is depressed.
If we were guessing, we'd say that GM will debut the rebirth of the tech on the Buick LaCrosse – a model that has enjoyed equal success in China and has the potential to revitalize the brand in the U.S.