I don't have an accurate mpg for it as I try not to work I out.
A long rung from leeds to Edinburgh (2 adults and 3 kids) 500 miles for about £80, the route is a steady one with some cruising 50/60 mph bits. So that's about 39mpg round town it's worse or course maybe 29ish. I do a motorway run of about 120 miles for little over £20.