Yes! We automatically determine how to display mileage data based on your country and region format.  We special case the UK because, even though it's on the metric system, they measure mileage in MPG and pump gas in litres.  We'll update the next version of our analysis to show that correctly.

In the meantime, if you're in the UK, enter in data as follows:

Enter in mileage in miles

Enter in quantity (although it says gallons) in litres

Enter price per litre in English pounds

In that way, the data collected will be correct.  

On the next upgrade, the analysis will display as expected - using litres with cost, and imperial miles used in mileage calculations.

Keep an eye out for the update!