I have done about 4400 miles now since 3rd March. I do a mix of town driving, A-Roads and motorway. Overally now I am averaging about 32mpg and I don't drive it like an old granny!!

Even when I did my Prodrive day, I did a total of 230 miles during the day including driving there and back and giving it some grief round the track and still achieved 30mpg.

If you are only getting 18mpg I think you may have a hole in the tank!!!