Most cars these days are driven by an internal combustion engine (ICE) (diesel or gasoline). This is going to change, with the goal to reduce greenhouse gas emissions and noxious pollutants such as particulate or nitrogen oxides. On the one hand, an ICE can be combined with electric motors (hybrid car), and on the other hand, a car can run completely on electric power (electric car). It is possible to have one electric motor or to fit each wheel with its own electric motor, preferably in the hub. Hybrid technology sometimes is considered a transitory technology towards completely electric power trains [194].