A motor fuel is a fuel that is used to provide power to the motor in motor vehicles. Currently, the majority of motor vehicles worldwide are powered by gasoline or diesel. Other energy sources include ethanol, biodiesel, propane, compressed natural gas (CNG), electric batteries, and hydrogen (either using fuel cells or combustion). There are also cars that use a hybrid of different power sources. The use of alternative fuels is increasing, especially in Europe. Before deciding on a particular fuel type, some factors should be considered: