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Tire advice: 215/50r17 vs 215/45r17 on Aftermarket rims

Discussion in 'Gen 2 Prius Accessories & Modifications' started by Jay-P, May 23, 2012.

  1. Jay-P

    Jay-P New Member

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    Hey guys, I need your help. I just bought some 17x7 wheels for my Gen2 and threw on some 225/45r17 ContiProContacts but Im still experiencing a 5-6 mpg loss.

    I heard that Goodyear Assurance Fuel Max is now available in 215/50r17 215/45r17. Does anyone know what the better tire is in terms of mileage and change in odometer?

    Or if anyone can recommend another tire that would be greatly appreciated as well. Thank you.
     
    #1 Jay-P, May 23, 2012
  2. F8L

    F8L Protecting Habitat & AG Lands

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    The 225/45/17 is the wrong size for a GenII. It is too tall. You are better off with a 215/45/17. It is narrower and closer to the OE 15" tire diameter.

    You will likely always suffer a 4+mpg loss with the 17" wheel on that car. Once you learn to hyper mile the difference can grow to 8mpg! You can try to reduce the hit by buying a more efficient and long lasting tire like the Ecopia EP422. It should produce at least 2mpg better than the ProContact but handling and traction will be reduced. Keep in mind that any new tire is going to require a break in before it reaches its full potential and it will continue to increase in efficiency as the tire wears down. So even if you replace your old tires with the exact same model you will experience a short term loss of mpg.

    As far as I can tell the EP422 is your best choice for mpg in that size. The Primacy MXM4 (V) is the best somewhat LRR tire in that size but mpg is not its main priority. The Nokian enTYRE would be nice but they are pricey.
     
    #2 F8L, May 24, 2012
  3. sidecar

    sidecar Member

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    the point is if the rolling diameter is out, all the instrumentation will be out too. F8L pulls the relevant data of the spec sheet as to how many revolutions per mile.

    although for the life of me i cant remember what that number is now :D
    844 ?
     
    #3 sidecar, May 24, 2012
  4. F8L

    F8L Protecting Habitat & AG Lands

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    Correct. 844 revs/mile is the number I generally use for the 215/45/17. The OE 185/65/15 Integrity tire is 855 but most of the common aftermarket tires in this size are 848-859. It appears that these numbers are close enough that the speedometer is not drastically affected by the change in size. A 205/45/17 would work well As they are the same diameter as the OE 15") but there are almost no LRR tires available in that size. The Contiental ExtremeContact DWS does come in that size, however.
     
    #4 F8L, May 24, 2012
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