I've had these on for about three weeks. No real change in mpg. Have been getting a lot of kidding about the name GFE. I did have one problem, tho. I put the pressure at 42/40 per John's recommendation and the car handled really, really horribly at high speed (55-70 mph). We dropped the pressure down to the recommended 35/33 and no problems. They seem to handle well enough in the Oregon rain and fog, but then with only a few weeks on them who knows? And who knows why they picked THAT NAME for the tires