Our free tool converts between litres and gallons, so you can see exactly how much fuel it takes to fill your tank.
We measure economy by miles to the gallon, but we measure in litres at the fuel pump – here you can convert between the two so you can more accurately judge your car’s fuel economy.
car tests discover a car’s true mpg by simulating a rolling road in a lab, which means every car can be tested in the exact same way, and in the exact same environment.
The test roads imitate city, out-of-town and motorway driving – something that the official tests don’t do – which allows you to see how the mpg could affect your pocket depending on the roads you typically drive on.
Our tests reveal that many car trip computers give inaccurate fuel-economy readings. To discover your car’s true mpg, try using the Which? car fuel calculator.
It allows you to work out the amount of fuel you used on recent trips, and see exactly how much you ended up paying for single journeys.