MPG Difference with H or T-rated Tires

Discussion in 'Fuel Economy' started by greenrider, Oct 23, 2008.

  1. greenrider

    greenrider Well-Known Member

    I'm about to buy Nokian WR G2s for my HCH II and have a question regarding speed ratings. Obviously, differently-rated tires have higher or lower speeds, depending on the rating. As for the different ratings, are the compounds they are constructed from different and would a lower or higher rated tire perform better from a fuel economy and LRR standpoint? Speed isn't a concern, but MPGs and winter handling are big issues up here in northern Illinois.

    Thank You!
     
  2. Showbizk

    Showbizk Well-Known Member

    It's a bit embarrassing that I work for the largest tire co. in the world, and AFAIK, no tire manufacturer publicizes (and maybe doesn't even test) rolling resistance (RR) for their tires. I also know however that my company is designing tires for lower RR. I found some information here that will be helpful, I think...
    http://greenseal.org/resources/reports/CGR_tire_rollingresistance.pdf
     
  3. voodoo22

    voodoo22 Cheaper than the bus

    I can't give you the kind of feedback you're asking for, but I can tell you that I bought a set of Nokian rSI's last year and got fantastic mileage and amazing traction with them. I will continue to buy Nokians until I have a bad experience, that's how impressed I am with them. It was the 2nd worst winter on Toronto's record for snow and ice and I literally could not make the ABS kick in when I tried. Only once all year did I lose any traction at all and ABS kicked in. One day in several inches of snow I was easily passing everyone the the tires just wouldn't slip and took the car where ever I pointed it. One day at a uphill redlight with a ridge of snow in front of my car left behind by the snow plow I pulled away from an Explorer which stuggled to get through the ridge. Amazing tires.

    I consistently got over 44 MPG with these aggressive winter tires which are supposed to be somewhat LRR and are R rated and I was not driving as disciplined as I do now.

    My personal opinion is you'll be very happy with the performance of your Nokians if they are made with the same quality as the ones I purchased last year.
     
  4. CapriRacer

    CapriRacer Well-Known Member

    OK, here's the deal:

    ALL OTHER THINGS BEING EQUAL, an H rated tires will have more RR than a T rated tire. This is because an H rated tire will almost certainly have a cap ply, where a T rated tire will probably have just cap strips. This means the H rated tire will have more material in the tread area - and more material means more RR.

    ADDITIONALLY, H rated tires tend to be designed for better handling, and the tread rubber compounds would be grippier and that also negatively impacts RR.

    BUT, higher speed rated tires are also more capable, so the risk of a tire failure is lower with an H rated tire than a T rated tire.

    But these are generalizations and you will find there are a lot of factors involved. You could get different results unless you pay attention to the details.
     

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