As above, take a book figure and knock a few MPG off and you will be close - on a gentle day! It's a VXR, you will be caning it here and there. A friend of mine has one and gets 28mpg from his.
My nurburgring VXR rarely returns 30mpg. I get perhaps 26 avg. On a trip up to Inverness, reset trip computer and on motorway driving roughly 80mph, did`nt get over 37mpg. It do drink fuel, hey ho. lol