Fuel consumption of any means of transport (car, aero plane, ship etc.) that uses fuel is a measure giving the relationship between the distance traveled for an amount of fuel used. The most common example is the car where it is usually expressed (in Englishspeaking countries) in miles per gallon.
It could also be expressed in gallons per mile. However, for a car the latter method gives a rather small figure: 35 miles per gallon is about 0.0286 gallons per mile. In that case it would be better to give a figure for 100 miles, so it would be 2.86 gallons per 100 miles. That is the metric way of expressing fuel consumption 
as liters per 100 kilometers.
From regular enquiries it appears that in real life people are using all sorts of ways of expressing their fuel consumption, so this section (unlike all the others) tries to cover as many ways as possible. All the values are given to an accuracy of 4 significant figures.
To
change
into
miles
per
gallon
(UK)
miles
per
gallon
(US)
multiply
by
0.833
miles
per
gallon
(UK)
miles
per
litre
multiply
by
0.22
miles
per
litre
miles
per
gallon
(UK)
multiply
by
4.546
miles
per
gallon
(UK)
kilometres
per
litre
multiply
by
0.354
miles
per
gallon
(US)
miles
per
gallon
(UK)
multiply
by
1.2
miles
per
gallon
(US)
miles
per
litre
multiply
by
0.2642
miles
per
litre
miles
per
gallon
(US)
multiply
by
3.785
miles
per
gallon
(US)
kilometres
per
litre
multiply
by
0.4251
X
miles
per
gallon
gallons
per
100
miles:
divide
100
by
X
(both
gallons
must
of
the
same
type)
X
miles
per
gallon
(UK)
litres
per
100
km:
divide
282.5
by
X
X
miles
per
gallon
(US)
litres
per
100
km:
divide
235.2
by
X
X
km
per
litre
litres
per
100
km:
divide
100
by
X
X
miles
per
litre
litres
per
100
km:
divide
62.14
by
X 
