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mixing tires - I know it's bad but . . .

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by shaun, Mar 28, 2010.

  1. shaun

    shaun Junior Member

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    Hi all,

    I have a set of all season 19570r14 tires (on rims) from another car that I'd like to use on the rear tires of our prius. The other car doesn't get much mileage anymore, so I feel these tires will be going to waste soon (due to age). Now you may ask, why not put them on all four? Well, we were going to do that with our 19570r14 winter tires originally so we wouldn't have to buy another set when we first got the prius, but the front calipers don't allow for 14" rims.

    So my question is how much of a world of trouble are we going to be in mixing tire sizes (19570r14 vs. the prius' 18565r15)? Another way of asking it could be: How much am I going to be chided/admonished by the tire shop when we go in to get new tires (18565r15's) for the front? We know we need new tires all around, but it'd be nice to only fork over $300 instead of $600, and get some use out of a set of tires we already own and aren't using to the full extent.

    Any thoughts would be appreciated.


    Thanks,

    Shaun
     
    #1 shaun, Mar 28, 2010
  2. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
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    I think you should stick with 15" wheels and the correct tires for the sake of safety and good handling. Yes, you can expect that the tire store will question your installation of under-size wheels on the rear axle.

    If you are paying $150 per tire, maybe you need to find another tire retailer or else buy tires mailorder from a place like tirerack.com?

    I usually buy tires from either Discount Tire or Costco. Discount Tire has a number of reasonable choices in the $70 - $100 range. Add the usual amounts for mounting/balancing and sales tax.
    Tire Products By Vehicle - Discount Tire
     
    #2 Patrick Wong, Mar 28, 2010
  3. vegasjetskier

    vegasjetskier New Member

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    I think you would be OK as long as the outside diameters of the tires are within a few millimeters of each other.
     
    #3 vegasjetskier, Mar 28, 2010
  4. shaun

    shaun Junior Member

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    The price is tire, install, and tax (roughly thereabouts) - Cooper CS4's.

    Thanks for the opinions (on both sides, albeit). I question it myself in terms of safety, handling, etc.. What makes me think it may not be as significant is the fact the rear tire's contact patch is only 10mm wider than the front tires (total) and have a 5% higher aspect ratio. When we originally were planning to install the older car's winter tires, the shop felt the 19570r14's wouldn't affect the speedometer as the difference was (if memory serves me), 2% from the stock prius tire.

    Speedometer readings are front wheel dependent, so putting the 14" tires in the back won't be a factor. Not sure if tracking will be, what with the 10mm wider tire in the back.

    I go back and forth on whether I should do it. :juggle:

    The dilemma's of the indecisive . . .

    Thanks for the responses so far :) I'll let you know what the tire shop thinks about my malarky if anyone's inclined to hear.
     
    #4 shaun, Mar 28, 2010
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