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new tires, lower mpg

Discussion in 'Gen 2 Prius Fuel Economy' started by rad911, May 5, 2009.

  1. rad911

    rad911 New Member

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    hello to all of you experts. i was getting close to 48 or 49mpg with a mix of highway and street driving and feeling pretty good about it. last month i changed my tires to some random costco tires, and now i am at 42 mpg. i recently did a 4 wheel alignment at the stealer for $140 and no change. is this common? is there a tire break in period or did i buy the wrong tires? very sad.
     
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  2. seasalsa

    seasalsa Active Member

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    Same size tires or did you go for larger tires?
     
  3. msirach

    msirach Member

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    New tires will have a certain run-in period. Michelin Energy that I put on a HCHII had about a 3000 mile before it was back to normal.

    Random tire? It's very possible that you increased rolling resistance exponentially by putting "any" tire on the Pri.
     
  4. morpheusx

    morpheusx Professor Chaos

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    when I changed my tires back in November. I went with wider 195/60R15 tires as I wanted to add some handling and stopping power and the tires I wanted also didn't come in the stock size. Anyway it took about 3000 - 5000 miles (hard to determine because of the extra cold winter this year), but my MPG is back to about 58 MPG now that its warmed up a little.
     
  5. drees

    drees Senior Member

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    I'm guessing you got the BF Goodrich Traction T/A as they were significantly cheaper than the Michelin's.

    My dad did the same thing for his Prius and he's been complaining about how poor his fuel economy has been. He normally gets close to 50 and now it's low/mid 40s with the new tires.

    They've slowly been getting better with more miles on them and after inflating them to 42f/40r. I'd estimate you'd need to get at least 10k miles on the tires before you start getting close to the same fuel economy as before.

    I really wish they'd hurry up and already make rolling resistance information information available on the sidewalls of all tires like the rest of the tire performance information.
     
  6. matt b.

    matt b. Member

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    you need low rolling resistant tires 27'6 the yokohama manufacturer. your mileage could get worse, take them back and get the s33 yok
     
  7. Mendel Leisk

    Mendel Leisk Senior Member

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    If the OP doesn't come back to clarify "random Costco tires" this is going to get old real quick.
     
  8. Bmr4life

    Bmr4life Member

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    Lol this thread is from 09

    ADR6425LVW ? 2
     
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  9. F8L

    F8L Protecting Habitat & AG Lands

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    Matt. Please refrain from giving out bad information like this. You're not even in the correct forum. The GenII didn't even come with Yokohama tires! :p

    Damn zombie threads. LOL
     
  10. uart

    uart Senior Member

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    See. Mendel was right!. :ROFLMAO:
     
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  11. Mendel Leisk

    Mendel Leisk Senior Member

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  12. ataylorracing

    ataylorracing ataylorracing

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    We have no experience with replacement tires yet....EXCEPT...our same size studded snow tires at the same air pressures as the original equipment tires killed our 50 mpg all around town to 43. The studded snows are a half pound heavier, but I definitely think the rolling resistance is the biggest problem. Last year there was only maybe one day of driving in glare ice that these tires work best at, 4 times this year. We don't mind having better glare ice traction for a reduction in mpg though. We can drive much better than 4wd big trucks.
     
  13. FuelMiser

    FuelMiser Senior Member

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    I also put some cheaper "random" tires on a few sets ago, and noticed an immediate drop in mileage. I did the math and determined increased fuel costs way outweighed the savings on the tires. Last two sets have been Continental Pro Contact Eco Plus and am happy again with MPG.
     
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  14. F8L

    F8L Protecting Habitat & AG Lands

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    Did this loss account for weather too? I.e. you swapped to the winter tires and noticed the loss immediately? If so please tell us which tires you have for summer and winter. :)