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Mileage dropped after new tires

Discussion in 'Gen 3 Prius Fuel Economy' started by [email protected], Jun 23, 2021.

  1. Racerman15@comcast.net

    [email protected] Junior Member

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    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.
     
  2. bisco

    bisco cookie crumbler

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    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
     
  3. Mendel Leisk

    Mendel Leisk Senior Member

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    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.
     
  4. Grit

    Grit Senior Member

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    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.
     
  5. ASRDogman

    ASRDogman Senior Member

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    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.
     
  6. farmecologist

    farmecologist Senior Member

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    Yep..lots of threads here about MPG dropping with new tires.

    Pro tip after reading tons of these threads: Let 'em break in! (y)
     
  7. bisco

    bisco cookie crumbler

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    by 80,000 miles, you'll be back to your old mpg's :D
     
    Priusjames and Mendel Leisk like this.
  8. Mendel Leisk

    Mendel Leisk Senior Member

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    Yeah, the ONE tire I saw that really hit-the-ground-running for mpg, was Bridgestone Ecopia EP20. I think they've discontinued it.
     
  9. Grit

    Grit Senior Member

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    that’s if you cleaned your egr circuit and put in a occ :eek:
     
  10. ASRDogman

    ASRDogman Senior Member

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    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...