VANOS (Variable Nockenwellen Steuerung) is an automobile variable valve timing technology developed by BMW in close collaboration with Continental Teves. VANOS varies the duration of the intake valves by moving the position of the camshafts in relation to the drive gear. This movement varies from 6degrees of advanced to 6degrees of retarded camshaft timing. BMW recently began offering 'double' VANOS, which operates on the exhaust camshaft as well, on a number of its cars.