Mr Jacob, you are responsible for the locking systems employed in M automobiles. We would like to talk to you today about the Active M differential in the BMW M3 and BMW M4. We wish to begin with the following question: why does a car actually need a differential?
Bernd Jacob: A car needs a differential to compensate for rotational speed differences in the wheels, for instance when driving through a bend. Since the vehicle has a certain width, the wheels on the outside of a curve are required to travel a greater distance than the wheels on the inside of a curve. This means that the outer wheels must rotate faster than the inner ones. To achieve this, a differential is fitted between the wheels of the drive axle – in the case of the BMW M3 and M4, this is the rear axle.