19 lb vs 24 lb tires

Discussion in 'Gen 3 Prius Main Forum' started by macmaster05, Nov 26, 2021.

  1. macmaster05

    macmaster05 Senor Member

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    I’m looking at 2 types of Pirelli tires for my 2010 Prius, both are described as LRR but one is 19 lbs ($10 more expensive/tire) and one is 24 lbs. Same exact dimensions. Both given a 70,000 mile tread warranty. Does anyone know what the theoretical mpg differences would be between them?

    I wanted to add this is on FR-S 17” rims, so I need all the mpg I can get lol. Thanks!
     
    #1 macmaster05, Nov 26, 2021
    Last edited: Nov 26, 2021
  2. xliderider

    xliderider Senior Member

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    Since you're already going to a heavier 17 inch wheel than the stock rims, you should definitely get the lighter of the two tires.

    You don't want the weight farther away from the center of rotation, which is what you are getting with the larger diameter wheel. So minimizing the weight, by getting the lighter tire, makes sense.

    The $40 price difference is probably worth it, and you'll likely get it back in time with fuel savings over the heavier tires.

    The other factor is the "butt dyno", the heavier tires will feel slower, and you'll take longer and have to rev the engine harder every time you accelerate to get to speed. So if you drive a lot of city miles, with a fair amount of stop and go, you want lighter tires. If you drive mainly highway or freeway miles, then maybe you can get away with the heavier tires.

    Posted via the PriusChat mobile app.
     
  3. xliderider

    xliderider Senior Member

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    FYI, the FRS rims on a Gen 3 in the past required a 3mm spacer to clear the rear brake caliper holder.

    The 16 inch old school Subaru Impezza WRX rims I put on our 2011 clears the rear caliper holder by about 1mm, a bit close for comfort, so I put 3mm spacers on for peace of mind.

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  4. macmaster05

    macmaster05 Senor Member

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    Thanks! Just ordered a set of Pirelli Centurato P7 All Season Plus IIs for a total of $528 including install. $170 off. Tread rating is 700. These are LRR supposedly and only weigh 19lbs. I can't wait!
     
  5. 3PriusMike

    3PriusMike Prius owner since 2000, Tesla M3 2018

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    If you get ~50 mpg (baseline) and go 70K miles you'll be using 1400 gallons of gas. At about $3/gal (adjust for your local area) this is $4200.
    If you get a 1 mpg improvement, this is about 1/50th of that or $84. About 2x the price difference.

    Mike
     
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  6. xliderider

    xliderider Senior Member

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    Do you need the spacers for the rears? Were you able to test fit the rims on the car? If you do need spacers, try to get ones that are hubcentric. I was able to find 3mm 5x100 spacers with the proper 54.1mm centerbore.

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  7. macmaster05

    macmaster05 Senor Member

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    Wheels already have spacers
     
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  8. Tombukt2

    Tombukt2 Active Member

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    I've had wheels so close on a car that the calipers actually made a small void in the alum wheels backside . Never an issue either . The tire place thought it was pretty cool it ran through about 9:00 sets of tires.

    SM-A715F ?
     
  9. Tombukt2

    Tombukt2 Active Member

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    Oh and I run cheap tires from Poland 17s weird size too like what do we get boo 245 55 17 and their LRR and all that and cost us like 48 bucks a pop and they roll pretty good for close to 40k and I like that because the tires don't do well in the southeast they're not black but for about 3 months and then they turn white all of them even the Michelin defenders all you're doing is spraying more tire shine and tire black on them trying to abate the sun. So I like about a 14-month turnover and then I'm putting new shoes on her

    SM-A715F ?
     
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