Under the Hood

The 640i is powered by a 315-horsepower, turbocharged 3.0-liter six-cylinder engine. Its peak torque rating is 332 pounds-feet. BMW cites a zero to 60 mph time of 5.5 seconds for both the coupe and convertible. The standard eight-speed automatic transmission includes steering-wheel-mounted shift paddles.

Other standard features include computer-controlled adaptive shock absorbers and Driving Dynamics Control, which allows the driver to adjust the ride quality, accelerator response, power-steering assist level and automatic transmission behavior.

Optional mechanical upgrades include active stabilizer bars and active steering, the latter of which adds rear-wheel steering to the earlier generation's variable-ratio front steering system.

    See also:

    Tire tread
    Summer tires Do not drive with a tire tread depth of less than 0.12 in/3 mm. There is an increased danger of hydroplaning if the tread depth is less than 0.12 in/3 mm. Winter tires Do not driv ...

    Folding forward
    Press the button, arrow 1, and fold the head restraint forward. ...

    Radio
    When the same radio source is selected in the front and rear (e.g., FM/AM), the same radio station is played. Operation is the same as for the front radio. ...