15 miles to work and 18 miles home, so roughly 165 miles a week ~ £45-£50 in fuel, overall with commuting and social driving I cover just over 1000 miles a month.
God bless the school holidays, it's taking me around 30 minutes to get to work, that's a 10mile drive to get to Oxford then a 5 mile drive through Oxford with naff all traffic at 8am

I take a different, more scenic route home, hence the +3 miles difference on the way back