We just added support for viewing the site in Imperial MPG. If you're in the UK, you probably want this option.
Hit the UK link in the upper-left corner of any page to start viewing the site in Imperial Units. Like the Metric option, you'll still see Litres and Kilometers on car profile pages, but the fuel economy rating will be in MPG Imperial (Miles/Imperial Gallon). We call it UK MPG for brevity.
As we understand it, you can't actually buy petrol by the Imperial Gallon anymore so we don't have that as a fuel-up option. This conversion is strictly for reading the site in UK MPG.
Let us know here if you spot any problems or find a place the conversion isn't happening.
I find the input very difficult. We measure fuel efficiency in miles per gallon but we buy in litres and so I have no idea how many gallons I've used or how much per gallon it costs.
Can we have Miles since fuel up, litres used and price per litre but then showing miles per gallon? I can't fill mine in on the move as I have to do the math to fill the forms in!
I show you are currently tracking using "Trip Miles" or miles from last fill-up.
You are currently reporting units in US Gallons instead of Liters as well as Miles instead of KM. You can make these changes by Editing Your vehicle.
More info can be found in this FAQ: http://www.fuelly.com/faq/7/reporting-units