51 mpg to L/100 km
51 mpg is 4.61 L/100 km when the figure is measured in US gallons, or 5.54 L/100 km in imperial gallons. Which one applies depends entirely on where the number came from — a US window sticker and a UK brochure use the same two letters for different volumes.
- L/100 km (US)
- 4.61
- from 51 mpg US
- L/100 km (imperial)
- 5.54
- from 51 mpg imp
- km/L
- 21.68
- US basis
- mpg imperial
- 61.2
- same car as 51 mpg US
The working
US: 235.21 ÷ 51 = 4.61 L/100 km
imperial: 282.48 ÷ 51 = 5.54 L/100 km
where 235.21 = 100 × 3.785411784 ÷ 1.609344
282.48 = 100 × 4.54609 ÷ 1.609344Nearby figures
Questions
›What is 51 mpg in L/100 km?
51 mpg is 4.61 L/100 km if the figure is US, or 5.54 L/100 km if it is imperial. Divide 235.21 by the mpg for US gallons, or 282.48 for imperial.
›Is 51 mpg good?
Yes. At 4.6 L/100 km this is hybrid or efficient-diesel territory, well ahead of the typical petrol saloon.
›What is 51 US mpg in UK mpg?
About 61.2 mpg imperial. The imperial gallon is 20% larger, so the same car always scores higher on the UK scale — which is why the two are not interchangeable.
Want the running cost rather than the conversion? Open the fuel cost calculator.