Plug-in hybrid cars use both a combustion engine and an electric motor. To recharge the battery that drives the electric motor, they are plugged into a power supply when stationary. Audi has a growing range of plug-in hybrid models. All offer the economy of an electric motor, backed up by the performance and reliability of an Audi combustion engine. They have three driving modes; purely electric, purely combustion, or an automatic combination of both.