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Ron3rd's avatar
Ron3rd
Explorer III
Dec 12, 2017

Max PSI rating on Trailer Wheels?

My trailer's Alloy wheels are 15 x 6, 5-lug. The load rating stamped on them is 2150 lbs. It came with 225-75-15, load range C tires, which run 50 psi. These tires are are marginal IMO for the trailer which has a gross weight of about 8600 lbs.

When I replace the tires, I'd like to go with load range D tires that run at 70 psi. How do I know from the specs on the wheel if they can handle the higher psi?

29 Replies

  • Ron3rd's avatar
    Ron3rd
    Explorer III
    JIMNLIN wrote:
    A wheel with a 2150 lb capacity is limited to 50 psi which corresponds with a C tire.

    Now if the 15" wheel had a 2680 lb or higher load rating then the 65 psi D tire will work.

    A 6 lug 15" wheel with a 2830 lb rating will handle a load E tire at 80 psi.

    A 8600 lb TT may have close to 1000 lbs on the tow vehicle leaving 7600 ln on the trailers axles or 1900 lb on the wheels. Now add a good 15 % reserve capacity = 2185 lb.
    Let your trailers axle ratings dictate tire and wheel selections and figure a 10-15 percent reserve above them.


    That's the answer I was looking for!
  • A wheel with a 2150 lb capacity is limited to 50 psi which corresponds with a C tire.

    Now if the 15" wheel had a 2680 lb or higher load rating then the 65 psi D tire will work.

    A 6 lug 15" wheel with a 2830 lb rating will handle a load E tire at 80 psi.

    A 8600 lb TT may have close to 1000 lbs on the tow vehicle leaving 7600 ln on the trailers axles or 1900 lb on the wheels. Now add a good 15 % reserve capacity = 2185 lb.
    Let your trailers axle ratings dictate tire and wheel selections and figure a 10-15 percent reserve above them.
  • If upgrading tires (rubber), have a serious look @ ST235/80R16. Might be worth the +1 upgrade on both rubber and rims / assume available space within the fender well... Especially if you plan to keep your RV for many more years...
  • I agree with a tire upgrade and went from LR C to LR D, highest possible I found for the 14 inch tires on my TT but would have Es if available. Ds take 65 psi max while Es should be inflated to 80 cold.
  • Ron3rd wrote:
    My trailer's Alloy wheels are 15 x 6, 5-lug. The load rating stamped on them is 2150 lbs. It came with 225-75-15, load range C tires, which run 50 psi. These tires are are marginal IMO for the trailer which has a gross weight of about 8600 lbs.

    When I replace the tires, I'd like to go with load range D tires that run at 70 psi. How do I know from the specs on the wheel if they can handle the higher psi?


    they are good to the load specified. so if the load range D are 2150 lbs or less at max pressure you are good to go.

    It's common that the 5 lug wheels are good for LRD and the 6 lug to LRE.

    If they are steel wheels they sometimes have a max pressure stamped on the as well.
  • Your rims will be fine with the 65psi that LR D tires take. I change from C to E ply rating on my trailers, no problems in 20 years or so.