Plug-in hybrid vehicles combine a conventional combustion engine with an electric motor. Intelligent interplay between the two saves fuel, lowers exhaust emissions, and provides an exceptional driving sensation. On journeys up to approx. 40km/h, a plug-in hybrid generally runs on pure electric power - provided that it makes sense, such as in urban areas. For maximum efficiency in different driving situations, such as on longer journeys or rapid acceleration, it uses the combined power of the electric motor and the combustion engine. If the battery which powers the electric motor has no charge, the vehicle will solely rely on the combustion engine.