2013 mileage dropped from 52 to 45 mpg after replacing Michelin Defender XT Passenger S/T tires with Michelin Defender T+H at 169K miles. I can understand that new tires will have a bit more friction but this was a big difference. It has improved only slightly over 30k miles. I have tries the spec tire pressure and higher pressure of 39 psi and no change.
also, the new tires have a larger rolling diameter, so the car travels further without the computer knowing it, which is based on revolutions. so your mpg's aren't as bad as the caris reporting. as with any tire, you have to look at specs and reviews
Ours took a significant hit, going from well-worn Michelin Pilot to Primacy. Both have Green-X badge (their LLR badge), but it doesn’t seem to carry much weight. Yeah, research; definitely DON’T just rely on manufacturer’s claims. Even then it can be a crap shoot.
if you really want, you can go to a independent tire shop and they can shave off the tread and leave 6mm on. mine took a 6 mpg hit with new tires. After 10,000 mi, got back to 65 mpg per tank. Now that summer is here, I’m yielding 67 mpg to the tank.
Mine improved, at least 4mpg with the new Bridgestone ECO tires. My speedometer is less than 1mph off, on the high side. And they are a lot quieter, and smoother. That was with 36psi, they now have 39. I gained back 4mpg I lost with the cooper tires. I'm very happy with them! I got them from walfart as a clearance for $81 each. If I had the money I would have gotten 4 more and saved them for they next time. I haven't driven much in the rain, yet.... But the little that I have they seem to grip well.
Yep..lots of threads here about MPG dropping with new tires. Pro tip after reading tons of these threads: Let 'em break in!
Yeah, the ONE tire I saw that really hit-the-ground-running for mpg, was Bridgestone Ecopia EP20. I think they've discontinued it.
I will be happy with 80,000 miles! And I'll get new tires. They are the Ecopia EP20's. They were discontinued tires. I've cleaned the egr circuit twice. And have already cleaned the spare/original cooler for the next time...