i drove for a couple days last week and got 60+ mpg (city, well known commute, amenable for pulse&glide). i rotated tires (or rather wheels) this weekend with unchanged tire pressure (~44psi). today i only got 50 mpg on the very same commute. is this just a coincident? edit: i did some more searches and a few other people posted similar things on the web. i should have explained that the rotation was done after driving (mostly hwy) for 8000 miles. I'm stretching the rotations a bit as there was little (visible) difference in the tread wear.
i've never seen anything dramatic enough to notice, but maybe your tyres need to break in again. are the factory oem? do you rotate front to back?
i guess this specific tire (continental purecontact) is very finicky and sensitive to break-in. when they were installed new, i lost 8mph (15%) over the well used OEM. if someone told me this, i would not believe it, but it happened. the mpg slowly came back over 20,000 miles, and now this. it's partially coming back though as i got 55mpg on the day 3 after the rotation. it was a cross rotation with both side-to-side and rear-to front.
update, after a week worth of driving (under 200 miles), the mpg gradually came back to where it was before rotation. there is about 2mm wear in 20,000 miles. thus the tires "should" last for 50,000 more miles.
I bought two of these recently and suffered the same fate, they were put on the front and threw the traction control light I think it was, some kinda limp mode (couldn’t exceed 55 or roundabouts) had to put them on the rear and it went away along with my precious fuel monies.........
