Fuel consumption is a measurement of the fuel used by an engine in a given time or to power a vehicle over a given distance.
The fuel consumption of a vehicle is measured using three common units:
- mpg(US) – miles travelled per US gallon
- mpg(UK) – miles travelled per UK gallon
- l/100km – litres used per 100km (used in Europe)
Usually fuel consumption is specified for more than one driving environment. For example, in Europe vehicle manufacturers quote three figures:
- Urban – for city driving
- Extra-Urban – for out-of-town driving
- Combined – a mix of Urban and Extra-Urban
Different measurement systems are used in engine testing (and in marine, aircraft and industrial engines). Here, fuel consumption may be measured in gallons or litres per hour. It can also be measured in fuel mass per unit time, for example grams per second (g/s) or kilograms per hour (kg/h).