I get 32mpg out of my non turbo 1.8 20v on a run and about 28.5 around town. The 1.8 20v Turbo is meant to be a lot better from What Car reviews. Urban states 32.1 for mine and 33.9 for the Turbo, thought it would have been the other way round!
I know Billy was getting low 20's in his old 20v Turbo, but that was running almost 200bhp. I think if he drove it well he could get around late 20's to early 30's.
Think TDI is the way to go these days. Heeeeeps of torque, fantastic performance and excellent economy! I went out in my mates Bora TDI thats had a re-map. That car is fast! Pulls like a train in every gear, I honestly could not believe the performance and this was from Tring to Milton Keynes, just over 20 miles, then to read the computer that read 39.8mpg........consdiering this was almost flat out all the way! Next car is def' a TDI Golf
