I've been running around in on 20inch shoed Xs for the last 30k or so. I have a set of referral 22inchers waiting to go on the car since last summer, but all the stories of HUGE consumption put me off fitting the wheels... However today just as we were about to set off on a 160 mile trip the tyre pressure indicator appeared!!! Despite having decent amount of tread left, the tyre was dead, and the 22inchers made an early appearance. I have to say regardless of consumption the X looks fab on 22s . So with the new boots off we went on a tour of UK motorways in Friday traffic, I set the max speed to 68mph, and about 1/3 of the trip was straight into a headwind with gusts of 40mph and rain, but I during traffic free stretches I noticed the energy use wasn't all much more than on 20s. The final consumption wasn't all that bad, especially given the conditions. Infact the consumption was virtually identical to the same trip done earlier this year in similar conditions. The time difference between the two trips was due to stationary traffic rather than speed. I recon in urban commute the range on 22s will be far worse than 20s, but long distance range appears to be not much more than 5% worse. By the end of this weekend we'll have covered another 400 miles, so will be interesting to see what the final figures are like. But initial impression are good, and going from 20 to 23s is no way nearly as bad as I feared.