Officially called "Auto Start/Stop," the system automatically switches off the engine when the car comes to a standstill. As soon as the driver puts in the clutch or depresses the gas pedal, the engine restarts automatically. BMW's "Intelligent Software" links together the various sensors required with the starter motor and the alternator control to make the process work.
Auto Start/Stop, along with BMW's High Precision Injection (lean-burn direct injection) and Brake Energy Regeneration technologies, will appear across a broad model range, with the Start/Stop technology to be introduced in four- and six-cylinder 1-, 3- and 5-Series models.
[Sources: BMW, Autocar]