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What should I inflate tires to?

Discussion in 'Gen 3 Prius Fuel Economy' started by mediahound, Jan 15, 2014.

  1. mediahound

    mediahound Active Member

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    I have 17" wheels and the tire manufacturer for the tires I have recommends 34 PSI front and rear. The max. is 50 psi.

    I understand inflating to near the max will help with gas mileage? I tried that but the ride is too bumpy.

    So, what should I inflate the tires to for the optimal gas mileage, performance and ride quality?
     
    #1 mediahound, Jan 15, 2014
  2. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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    I never inflate for gas mileage, I inflate for best wear. I want a flat contact patch with the same wear near the edge as the center. Side effects should be good handling, as I am laying down a lot of rubber, good braking as I have a lot of rubber on the road, and good mileage compared to 34 PSI.

    Sadly, the only way to find the ideal wear is trial and error and it varies by tire. On my Gen 2, the GoodYear Integritys wanted 42f/40r, while the GY Assurance Fuel Max only wanted 38f/36r. Same Car same load, different tire.

    I would try 40f/38r and adjust down in the ride is objectionable or the center wears faster than the edge, and adjust up if the edge wears faster than the center.
     
    #2 JimboPalmer, Jan 15, 2014
    bwilson4web likes this.
  3. mediahound

    mediahound Active Member

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    Thanks. I tried it at 50 PSI and the ride was really bumpy. I'm thinking about 40 PSI, which is still above what the tire manufacturer recommends, may be about right.
     
    #3 mediahound, Jan 15, 2014
  4. bisco

    bisco cookie crumbler

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    i do 42/40 and it's pretty comfy. don't know how different 17's are tho.
     
    #4 bisco, Jan 15, 2014
  5. Grren4ever

    Grren4ever Active Member

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    I have 17's with Toyo A20's. I keep the fronts at 34 and rear at 32-33. Been driving for 4 months now with the car and have no problem at all getting 4.4l/100km or something like 52mpg equivalent.
     
    #5 Grren4ever, Jan 15, 2014
  6. mediahound

    mediahound Active Member

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    Tread wear is even too?
     
    #6 mediahound, Jan 16, 2014
  7. Grren4ever

    Grren4ever Active Member

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    So far so good. Had a peek at the tires during the last car wash and didn't notice any sort of cupping or uneven wear. Besides, the manufacturer recommends 33f/32r for our 17's. However, I only have 6000km on the car - it is still pretty new so any uneven wear probably won't show up yet for me :)

    Looks like you have lowering springs. Do you notice any extra wear on the insides of the tires from negative camber?
     
    #7 Grren4ever, Jan 16, 2014
  8. mediahound

    mediahound Active Member

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    Not yet, but I only have 2000 miles on the car. It has been aligned with the lowering springs on however so I'm not sure if that adjusts for that.
     
    #8 mediahound, Jan 16, 2014
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