Autogas is a name for liquefied petroleum gas (LPG) which is used as a fuel in internal combustion engines in vehicles and in stationary applications such as generators. Autogas is a mixture of propane and butane. Autogas is the third most popular automotive fuel in the world. It has economic and environmental advantages, and represents a truly a green-green fuel. Autogas is cheaper than petrol or diesel, and qualifies for lower annual road tax rates – which provides significant cost savings for drivers.