New tires for my truck, Which ones??

Discussion in '4x4's, SUV's and P/U Trucks' started by deleond2, Sep 11, 2010.

  1. deleond2

    deleond2 Well-Known Member

    My Firestone Destination ATs have worn surprising well, I expect to get 55 to 60K at of them. Once they are gone, I'm looking to get a more highway friendly tire...........

    I'm looking at the..
    General Grabber HTS (high ranking in CR and highly ranked on tirerack.com)
    or
    Michelin M/S2 (highest ranked highway tire on tirerack.com)

    I have also looked at 3 different sizes......
    P265/70/17 (the size currently on my truck, about 31.7 inches in dia)
    P245/70/17 (stock size, about 30.6inches in dia)
    LT245/70/17 (about 31.7 inches in dia, it has an E load rating, it weighs more than the two tires above, but its max is about 80psi)

    A taller tire will decrease highway RPMs but raise the trucks height and worsen acceleration. The E load tire can be pumped up to 80psi to lower rolling resistance but with this be useless because of the extra wt?? Any suggestions??

    (please do not put any comments regarding how trucks are bad on gas, dont ask me why I need a truck. I have already addressed these issues myself. I'm already looking to purchase a more fuel efficient auto, likely a hybrid, when the money is right.)
     
  2. MaxxMPG

    MaxxMPG Hasta Lavista AAA-Vee Von't Be Bach

    Both tires (General HTS and Michelin M/S2) are listed as LRR tires on Tirerack. Neither are all terrain tires like the OEM Firestones, so confirm that you are using your truck on-road with some possible soft-road travel. The Generals are cheaper than the Michelins, but they look like they'd be similar when used on a daily driver.

    When shopping for truck tires, check the load rating (typically 115 for a half ton truck), as well as the usual treadwear/traction/temperature.

    The taller tire will decrease engine rpm slightly, and increasing tire diameter by one inch raises the chassis by about half an inch. More ground clearance can also mean more lift and aero drag, and an extra half inch of step-in height - which is a consideration for drivers with smaller inseams. I put slightly taller tires on my wifes car for better highway mpg and to underclock the odometer a little bit (101.6 miles traveled for every 100 miles on the odometer). The mpg stayed about the same - or more likely too close to measure with so many other variables that affect FE - so I wouldn't say it's a definite gotta-have for lower fuel consumption.

    The load range E tires are much heavier, costlier, and will ride stiffer than the stock tires. As you noted, the added weight will likely offset the higher pressure limit. Higher pressure means less rolling resistance, but your selection of LRR tires in your choices above will go a long way toward improving FE without having to press them up into "load range E territory".
     
  3. deleond2

    deleond2 Well-Known Member

    I'm part of the 95% (just pulled that out of my butt) of truck owners who never take their trucks off-road. The worst my truck has ever seen (in its 80K miles) was when I took a wrong turn at a drive-thru zoo and ran into some mud.

    Both the General and Michelins match the load ratings of the original tires. When you compare the the two above to the OEM General AmeriTracs, the OEM's suck horribly.

    When I switched to the 265/70/17 ATs, I wanted a taller, more aggressive tire because it looked COOLER.

    MaxxMPG, your message above is what I needed, It is best to back down to the OEM size of 245/70/17.
     
  4. MaxxMPG

    MaxxMPG Hasta Lavista AAA-Vee Von't Be Bach

    You will save a few bucks by going back to the stock size, and the narrower tire is always beneficial in terms of fuel economy. To go taller, you can always choose 245/75 instead of 245/70 for a .5" increase in diameter. But tires with soft sidewalls, combined with the taller aspect ratio, can make the handling numb. The reason today's pickups migrated from 75-series tires on 16 inch wheels to 70 series on 17 inch wheels was to improve steering response for more "car-like" handling.

    Narrower tires are also preferable for snow traction, and the only disadvantages would be some reduction in high speed cornering and low speed sand/gravel traction capability.
     
  5. msirach

    msirach Well-Known Member

    I would stay away from General tires. A lot of people around here use them because of price. More noise and usually more problems. I have had very good luck with Bridgestone tires and I know of several that have gotten up to 80,000 out of the Michelin. The Michelin are more quiet at higher psi also.
     
  6. deleond2

    deleond2 Well-Known Member

    MaxxMPG
    I agree with your thoughts on the 245/75/17, but all the tires I find in that size are the "E" ones. I was considering the 235/75/17, but w/ a lower load rating, I decided to pass that size up.

    Misirach
    Two yrs ago I would have felt the same way about the general tires, but the General Grabber HTS is something different. Consumer Reports rated it very highly and tirerack.com gives it a high rating. The user rating on tirerack.com is very high. The Michelin MS/2 are even better, but I dont know if paying the extra $40-$50 per tire on 5tires is worth only a small increase in performance/wear. The noise of the tire does not factor highly in my descion making process, the windows are down and the radion is usually cranked.
     
  7. CapriRacer

    CapriRacer Well-Known Member


    As surprising as it may seem, you may want to go wider AND taller. I outline that here:


    http://www.barrystiretech.com/rrandfe2.html

    The jist of it is that load carrying capacity plays a major role in RR - and while it may seem counter-intuitive, sometimes going wider increases the load carrying capacity - and therefore its affect on RR - faster than the additional material needed to make the tire wider.

    Also, do NOT use LT tires if you consider RR important. Only recently has RR been considerewd important enough by tire manufacturers to have dedicated lines of tires. LT tires with the same features are probably a decade away.
     
  8. Blaster94

    Blaster94 Well-Known Member

    I have been using general tires for about 5 years on my company cars. They ride well, wear well and have seen many tens of thousands of miles with no problems. I just replaced my tires on my tundra with yokohama geolander hts primarily because the cost was pretty low. I would have gone with the general grabber this time but it was about 150 dollars more and these tires will dry-rot before they are close to being worn out.
     
  9. deleond2

    deleond2 Well-Known Member

    I read the article, let me make sure I understand it..........

    The taller/rider tires have less RR because they usually have a higher load rating, and not just because they are taller/rider?? Using that logic..........

    Looking at the website for the General Grabber HST

    Tire #1 - 245/70/17 - 30.6inches - Load=108T(2205lbs)
    Tire #2 - 265/65/17 - 30.6inches - Load=112T(2469lbs)
    Tire #3 - 265/70/17 - 31.6inches - Load=113S(2535lbs)

    After reading your article.....#2 looks to be much better that #1, the small increase in width (while staying the same dia) yields a BIG improvement in Load capacity (and thus big decrease in RR). Even with the extra width, #2 should be more fuel efficient than #1.

    But when comparing #2 & #3, the improvement in Load Capacity with #3 is not that much. The article says the decrease in the RR (due to increased load) will usually overcome the negative effects of drag. Will the small improvement in Load capacity (w/ the resulting decrease in RR) be worth the extra inch in dia??

    Are my thoughts regarding tires #1, #2, #3 correct??
     
  10. CapriRacer

    CapriRacer Well-Known Member

    First, the article is based on just one study. It would be nice to have some confirmation. So take it with the appropriate grain of salt.

    Second, the extra inch in diameter reduces the overall drive ratio which ought to have beneficial effects beyond the tire itself, but I have no way to quantify.

    So I would tend to go with tire #3 - all other things being equal.
     
  11. deleond2

    deleond2 Well-Known Member

    I will try my best to sift through the info, of course this view point does muddy the waters a bit.
     
  12. Tallswede

    Tallswede Member

    I just recently purchased new tires for my Jeep Liberty. It originally had Goodyears on it from the factory 225/70/16. I went up one size to Pathfinder 245/70/16 because I wanted a little wider tire for flotation on sand/dirt and load carrying capacity. I bought the Pathfinders because I had good luck with them on an old Suburban of mine. I've found that the highway handling and ride has improved and fuel milage is about the same maybe a tad better. I keep them at 40 psi.

    Kevin
     

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