Fuel economy in automobiles

The fuel economy or fuel efficiency of an automobile relates to the distance traveled by a vehicle and the amount of fuel consumed. It can be expressed in terms of the volume of fuel to travel a given distance, such as in litres per 100 kilometres (L/100 km), or through its inverse, the distance traveled per unit volume of fuel consumed, as in kilometres per litre (km/L) or miles per gallon (mpg).