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Low Rolling Resistance replacement tires: Current List

Discussion in 'Gen 3 Prius Fuel Economy' started by F8L, Apr 17, 2011.

  1. cgm55082

    cgm55082 Junior Member

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    Okay, just made an appointment for new tires tomorrow. Going to try the EP 422. Hope it helps solve my poor mileage problems...
     
  2. alfon

    alfon Senior Member

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    I had them, and returned them during the 30 day money back Costco guarantee period. MPG's were at least
    2-3 mpg less than the Michelin Energy Saver AS tires I had on previously. Costco installed Energy Saver tires
    at my request and they handle much better and more MPG's....
     
  3. cgm55082

    cgm55082 Junior Member

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    alfon, that is interesting. Not disputing what you're saying, but the Tirerack test, which I trust given its methodology, ranked the EP100 an almost insignificant fraction (.3) less mpg than the Energy Savers. My understanding is the EP422s have an even lower LRR than the EP100s, so should deliver even better mpg. Tirerack's subsequent test, which included the EP422 and a handful of other LRRs, but did not include the Energy Savers, ranked the EP422 best for mpg among the tires tested. In that test it even beat the Conti ProContact EcoPlus for mpg, which seems to be a very well liked tire on this site. In fairness, I don't have experience yet with the EP422s, but the research I've done leads me to believe it's a pretty darn good LRR tire. I'd be interested in hearing from others who have real world experience with the EP422 to see if they had the same results you did. Thanks for your input -- makes us all more educated about the choices we make for our cars.
     
  4. alfon

    alfon Senior Member

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    Also I noticed at speed 65 plus mph the EP422 have a tendency to drift off track. This is rather annoying after
    hours of highway driving. The Energy Saver held true, with no drifting.

    I put on at least 3,000 miles during that month with the EP422 tires, went on vacation during that time,
    this is just my opinion, but if the EP422's were even just as good as the Energy Saver tires I would have
    kept them on.
     
  5. Chris S

    Chris S Active Member

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  6. cgm55082

    cgm55082 Junior Member

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    Another question for the forum: Would non LRR tires deliver the same or better mpg as LRR tires if they had more psi in them? Are we making too much of LRR's? I ask because the LRR tire I'm looking at has a max psi of 44, whereas my non LRR tires have a 55 max psi and I run them at 47 psi. Just curious if the extra psi offsets the more efficient treads of LRR tires?
     
  7. Britprius

    Britprius Senior Member

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    There are diminishing returns on raising tyre pressures.

    The max sidewall pressure depends on a number of factors including load and speed ratings for any particular tyre.

    John (Britprius)
     
  8. cgm55082

    cgm55082 Junior Member

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    John, did I read somewhere that you have the EP422s? If so, how do you like them?
     
  9. F8L

    F8L Protecting Habitat & AG Lands

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    No because higher pressure doesn't cure all of the things that negatively affect fuel economy. A good LRR tire addresses more than just sidewall deflection.

    Alfon is correct in that the Energy Saver A/S is more efficient than the EP422 and it performs better too. It is a little more expensive but the higher fuel efficiency usually evens them back out. The EP422 with the $70 discount could be a little cheaper overall but the Energy Saver A/S is still a better tire.

    The ProContact is not a very fuel efficient tire. It's a good tire but there are more efficient and longer lasting tires out there. As far as I can tell, the EP100 was more efficient than the EP422. The fact that the EP100 had a lower tread wear rating further demonstrates this as you cannot have ultra LRR AND longevity AND performance. You have to make sacrifices somewhere. :)

    That being said, the EP422 is a good tire but it gets knocked for poor handling. I noticed this in their 17" size as well. If you want max fuel efficiency and the Energy Saver A/S is not available then the EP422 is your next best bet for now.
     
  10. cgm55082

    cgm55082 Junior Member

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    Just wanted to report back. Took the leap yesterday on the EP422s. Instantly quiet as compared to my other tires. Amazing how quiet they are actually. I only have about 100 miles on them, but my mpg is definitely up. Not a surprise after the non LRR tires they replaced.
     
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  11. paprius4030

    paprius4030 My first Prius

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    Does anybody have any experience with Kumo ecowing KH30 tires? I believe they are fairly new and LRR tires. If nobody has any experience with them can you tell from the tech info if the mpg's would be just as good or better than the Goodyear fuel max tires? Thanks!
     
  12. F8L

    F8L Protecting Habitat & AG Lands

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    I'm not a big fan of Kumho tires. That being said, I have not seen any real tests with it so I can't make any comparisons. However, it seems like most of the time I read about a test where a Kumho tire is involved it usually ranks low. See the test below as an example of a similar tire.

    is the Tire Test Results : Eco-Friendly All-Season Tires — How Does Performance Measure Up?

    The tire is pretty cheap and Kumho lists it as a High Performance tire. That makes it suspect IMO. I'd look for a different tire unless you want to be the guinea pig. ;)
     
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  13. cinder

    cinder Member

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    CGM , keep us informed on performance and how much of a increase or decrease of gas mileage .
     
  14. F8L

    F8L Protecting Habitat & AG Lands

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    Did you get the 89H rated tires or the 91H rated tires?
     
  15. cgm55082

    cgm55082 Junior Member

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    These are the 86H EP422s. There is definitely a mpg gain already over the BF Goodrich non LRR tires I had on the car. Keep in mind, I had the Goodrich's pumped up to 47/45 psi and the EP422s have been at the factory recommended psi and I'm still seeing a gain. How much of a gain is questionable, because I changed my 12V battery two days before the tires. Even though the battery tested okay, I wanted to replace it as it was borderline. I saw about a 2 mpg improvement with that. The new tires seemed to add close to 3 mpg on top of that. I expect once I air them up to 42/40 and they get some wear on them, the mpg will be even better. Stay tuned...
     
  16. paprius4030

    paprius4030 My first Prius

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    Thanks F8L. Your provide lots of info here and a great service to us all!
     
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  17. Britprius

    Britprius Senior Member

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    Sorry for the slow reply but I do not appear to be getting all the alerts to posts.

    I run Hankook Eco Kinergy tyres in 205/55/16 size. They are a LRR tyre UK rated (B) for RR and (B) for wet grip.

    I find them a very good tyre at a very good price. At the rate of ware "now at 19,000 miles" they should be good for at leased 40,000 miles, this is very good for UK road conditions.

    They also return a constant 600 mile+ to a tank of fuel.
    IMG_0001.JPG
    John (Britprius)
     
  18. Britprius

    Britprius Senior Member

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    Just checked out Kumho tyres. They now have a tyre rated A B at 67db. This is available in two sizes at this rating:-

    Kumho Ecowing ES01. KH27 195/65/15 91H rated (A) for RR (B) for wet grip at 67db
    Kumho Ecowing ES01. KH27 215/65/16 98H rated (A) for RR (B) for wet grip at 69db

    Ware life unknown but good on paper for a budget tyre.

    John (Britprius)
     
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  19. F8L

    F8L Protecting Habitat & AG Lands

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    Why are the Europeans getting all the efficient tires? :(
     
  20. WilMent

    WilMent diacritic

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    No need to be jealous, they can keep their tires and "petro" prices :ROFLMAO:
     
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