I had my the tires on my 2009 Prius rotated a while back. My car has 36,000 miles on it all on the original tires. It seems like my mileage dropped a bit since doing that. There are so many variables in mileage though, it is hard for me to pin it down to that. Could tire rotation affect my mileage? Thinking of some Bridgestone Ecopia 100s from Tirerack.com as replacements.
Tire rotation should not have any impact on mpg. Did you check the tire pressures after rotation? I usually have to readjust the pressures after tire rotation even though I tell the mechanic what I want for final pressures. Wow, you have 36K miles on the original Integrity tires?!? I've never got much over 26K on my 04 or 09.
It could have an impact on mpg due to specific wear patterns on each tire. Your alignment at each corner is different and the tires may wear differently. When you switch the tires to different locations you may take a small mpg hit until the higher edges wear down. In most vehicles this may not be noticed but in very fuel efficient vehicles you may be able to calculate it. That's what I've read anyway.
+1 If you were running your tires at let's say 42 psi front/40 rear, there is a good possibility that the tech reduced the pressures to the Toyota recommended pressures on the door frame placard. This could lead to a 3-5 MPG drop. Some service facilities/techs mindlessly adhere to the idea that this pressure -- intended for ride comfort -- is the ONE AND ONLY pressure they will put in tires leaving their shop. It is safe to run tires up to the values shown on the sidewall of the tire. You will see better MPGs and better tread wear but some harshness in ride comfort.
