Convert MPG between US gallons and Imperial gallons.
Because the imperial gallon is bigger, the same real fuel economy reads as roughly 20 percent higher in miles per imperial gallon. UK and US figures are frequently misread as equal, which can badly skew comparisons of fuel economy between markets.
MPG Imperial vs US
MPG imperial = MPG US x 1.20095 (one imperial gallon is 20% larger)
MPG imperial = MPG US x 1.20095 (one imperial gallon is 20% larger) Because the imperial gallon is bigger, the same real fuel economy reads as roughly 20 percent higher in miles per imperial gallon.
UK and US figures are frequently misread as equal, which can badly skew comparisons of fuel economy between markets.
This calculator takes 2 inputs: MPG value, Given system. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.