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:

    The concept
    Integral Active Steering is a combination of Active Steering and rear axle steering. Active Steering varies the steering angle of the wheels in relation to the steering wheel movement as a func ...

    Installing child restraint systems
    Observe the child restraint system manufacturer's instructions when selecting, installing and using child restraint systems. Otherwise, the protective effect may be diminished. Standard chil ...

    Switching the interior lamps on and off
    Press the button. To switch off permanently: press the button for approx. 3 seconds. Switch back on: press button. ...