In 1996, nearly two years after the presentation of the new BMW 7 Series (E38), BMW launched a diesel model in the luxury class for the first time in the form of the 725tds. The six-cylinder power unit M51D25 provided with a charge-air cooler ensured superb ride qualities even in the luxury class thanks to an outstanding torque curve. Further diesel models with six-cylinder and eight-cylinder engines (like the BMW 730d and 740d) followed in 1998 and 1999. This established diesel drive units as a permanent fixture even in the BMW 7 Series.