What does this tool do?
A UK gallon is about 4.546 litres and a US gallon about 3.785 litres, so the same economy figure means different things in each country. This converter also switches to fuel consumption per distance, where a lower number is better.
The Formula
mpg UK = mpg US × 1.20095; L/100 km = 235.2146 ÷ mpg USFrequently Asked Questions
Why is UK mpg higher than US mpg?
The imperial gallon is about 20% larger than the US gallon, so a car covering the same distance uses fewer imperial gallons. The underlying efficiency is identical.
Is higher mpg always better?
Yes for fuel economy, but the opposite is true for litres per 100 km: a lower number means less fuel used. Be careful not to compare the two in the same direction.