I can regularly average 42mpg on my way to work (roads with a 50 limit) but I have hit 45 once, not through choice I might add. It's more like 33-35 including some town driving. It did go down to mid 20s in stop-start traffic over a couple of miles. I've heard there's not much difference between a 16v, an 8v and a non GTI 1.8. Lets face it though, most cars will have much better economy than a 2 litre turbo.