The concept

The automatic engine start-stop function helps save fuel. The system switches off the engine during a stop, e. g., in a traffic congestion or at traffic lights. The ignition remains switched on.

The engine starts again automatically for driving off.

    See also:

    On/off and tone
    The following audio and video sources share the same control elements and adjustments: > Radio > CD/DVD player > CD changer > Video > External devices, e.g. MP3 player ...

    Sound output
    Switching on/off When the ignition is switched off: press ON/OFF button on the radio. Muting When the ignition is switched on or the engine is running: press the ON/OFF button on the radio. ...

    Safety
    Both the coupe and convertible have front airbags plus side-impact airbags built into the front seats. As required of all 2012 models sold in the U.S., the 640i has standard antilock brakes and an ...