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New tires YOKOHAMA AVID ASCEND . Loss about 1-2 mpg. Not upset.

Discussion in 'Gen 2 Prius Fuel Economy' started by bobodaclown, Jun 6, 2019.

  1. bobodaclown

    bobodaclown Member

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    Hello All,
    Just replaced my tires all 4 from ECOPIA EP422 to YOKOHAMA AVID ASCEND and changed out front and rear shocks/struts. Nice change all the way around. Did the shocks/struts first. Used Monroe quick stuts in the front. Pretty easy job overall. Rode on the old tires for about 2 weeks or so. Just didn't have a chance to get the tires, and do the alignment. Handling was much improved. Didn't realize how worn the old suspension was.
    Was averaging (computed) about 44-45 mpg.
    Installed new tires, YOKOHAMA AVID ASCEND, wow, they are quiet compared to the old, worn EP422s. So far I'm satisfied, only about 500 miles on them. My daily commute is about 60 miles round trip, 20 local roads 35 mph, and 40 highway 70+mph.
    Tires are rated for 85K, I'm hoping to get 5 years or 75K out of them. Then the car will be 15 years old with over 200K, maybe time to replace. :)
    I'm in Southern California, south of Riverside, normally commute the 215. So haven't had bad weather to really workout the tires. But so far I'd recommend.
    Oh, the only unscheduled maintenance I've done is the inverter coolant pump (DIY $100), and brake accuator ($1800 ($1200 part/$600 labor) past extended warranty by 3 months). I've pretty happy.
     
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  2. Salamander_King

    Salamander_King Senior Member

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    Did you get regular YOKOHAMA AVID ASCEND or newer YOKOHAMA AVID ASCEND GT? Both are similary priced and have similar specs. The older ASCEND maybe going to be discontinued soon? I had ASCEND on my older cars, and liked it, but thinking of trying ASCEND GT.

    Yoko_Ascend.png
     
  3. jerrymildred

    jerrymildred Senior Member

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    I got the GT version and I love them. They did great in heavy rain. Not sure about fuel economy since I got them just as the summer heat hit.
     
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  4. bobodaclown

    bobodaclown Member

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    Non GT. $68 each.
     
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  5. srellim234

    srellim234 Senior Member

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    I went from the Pirelli Cinturato P7 A/S to the Avid Ascend GT at the beginning of April (April 8th to be exact). The initial hit with the new tires was a loss of 2-4 mpg for the first 1,000 miles or so but by 3,000 miles the tires were already delivering about the same gas mileage as the older tires. I expect them to get even a bit better as the tread wears down over time. The last five tanks have been calculated as 44.11, 42.33, 43.86, 43.3 and 45.12 mpg, right in line with or a hair better than the car's 42.89 lifetime average. I'll know a lot more about them when we return from driving to the East Coast and back in July..
     
  6. bobodaclown

    bobodaclown Member

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    So I've been running the tires about two weeks. I'm liking them. Was running then at 42/40 psi front/rear. Trying 50/48 to improve gas mileage. They are rated to 51 max psi. We'll see how it goes. Ride is a little firmer. The tires replaced were rated for 44 psi max.
     
  7. jb in NE

    jb in NE Senior Member

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    As the pressures go up, center tread wear also goes up and you beat up your suspension components a lot more. The savings in fuel at these pressures may be more than offset by these costs.
     
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  8. bobodaclown

    bobodaclown Member

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    I'd agree if we were talking bias ply tires, not radials.


    Tire Tech


    SM-T700 ?
     
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  9. jb in NE

    jb in NE Senior Member

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    Even radials will narrow the tread pattern at high pressure.

    "Excessive air pressure will cause the tread face to bulge, reducing the contact patch."
     
  10. bobodaclown

    bobodaclown Member

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    Is that pressure over the max rated?

    SM-T700 ?
     
  11. Mendel Leisk

    Mendel Leisk Senior Member

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    I think several not so good things can happen at extreme pressure:

    1. Increased suspension/bearing wear. (mentioned by @jb in NE)
    2. Punishing ride. (more so with the low-profile 17's)
    3. Maybe more tendency got lose lose grip over little bumps, especially when cornering?
     
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  12. jerrymildred

    jerrymildred Senior Member

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    I'm not sure there's anything to be gained by pumping them over 38-40 psi. If there's any increase in mpg, it'll be well within the range of other influences like weather and traffic, so not enough to be a clear measurement. And the Prime already gets such incredible mileage that I don't fuss about a couple psi and would not want to run my tires close to max psi.

    Another thing I've noticed is that at high pressures the steering gets kind of touchy since the car's weight isn't as even distributed across the tread. It may not wear faster in the middle, but radials don't completely eliminate the tires' tendency to get rounder at higher pressure.
     
    #12 jerrymildred, Jun 22, 2019
    Last edited: Jun 22, 2019
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  13. exstudent

    exstudent Senior Member

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    I hope you get lots of miles. Very few get close to the rated mileage claims.

    Making a mileage warranty claim is next to IMPOSSIBLE and oftentimes worthless b/c of the fine print. The biggest impediment against owners, in making a mileage warranty claim, is the requriement of even wear across the tire tread.

    That's some punishing PSI! You have a pretty high pain threshold?
     
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  14. bobodaclown

    bobodaclown Member

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    Pressure coming down. 45/43.
     
  15. Salamander_King

    Salamander_King Senior Member

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    Why? No change in mpg... or you bottom hurts?:LOL::LOL::LOL:
     
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  16. bobodaclown

    bobodaclown Member

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    Nah, I did new shocks and struts at the same time. ;)
     
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  17. srellim234

    srellim234 Senior Member

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    Boosting it high doesn't make a lot of sense in my driving conditions. I spend my summers running through the Mojave Desert at 65-75 mph. There may be a 40 or 50 degree difference in the morning between the air temperature in my garage and the highways I'm driving. Driving those conditions adds a minimum 4 or 5 psi. I just try to set them at 38 psi front, 36 psi rear and enjoy the drive without rattling my teeth or facing a blowout. Destroying the suspension, tires or my family is not worth a few mpg.
     
  18. bobodaclown

    bobodaclown Member

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    Lowered the psi 45/43 or so. Tires are great. Gaining the mileage back. Might be in limiting my speed.

    moto g(6) ?
     
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  19. bobodaclown

    bobodaclown Member

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    Back to 42/40. All is well.
     
  20. jerrymildred

    jerrymildred Senior Member

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    I have the same tires. Still love them. Had a temporary small reduction in miles/kWh. They are wearing great and still give superb wet weather traction after about 25k miles.
     
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