I think people pay too much attention to the onboard MPG reading. Mine consistently reads around 37mpg with a combination of sensible driving and some less than sensible driving I've just done a manual calculation and my REAL mpg is closer to 26mpg. I once hit 50mpg on a 15 mile trip (purposely granny driving) according to the computer - and I didn't reset it when the engine was warm, that was from a cold start - load of b****cks tbh.
I've owned my Cup for 1 week, and had 41.2 out of it. I don't by any means drive slow, but for normal driving it's an economical car imo