Tires: Heavy recreational trailer, gross vehicle weight, recreational trailer

Question
QUESTION: I have a horse/recreational trailer that weighs about 20-25 fully loaded. I have G rated tires on it now and i am still blowing tires. Am I using the wrong size tire or wrong rating? What rating would you recommend for 16" tires and this weight?

ANSWER: Carl,

I assume that 20 to 25 means 20,000# to 25,000 pounds.  That's quite a range.  So I suggest you weigh the trailer.  Weigh it hooked up to your tow vehicle and weigh each tire separately if you can, but at the very least weigh each axle individually.  Be sure to load the trailer to the max - full of white, gray and black water and everything you normally carry and everything you might possibly carry.  Your looking to get a worst case.

BTW, there might be a placard that lists the Gross Vehicle Weight (GVW) and it might not hurt to weigh the trailer by itself to see how the actual weight compares to the GVW.

But to try to put some numbers to this:  If the trailer actually weighs 25K, and we assume that 15% of the weight is carried by the hitch, then the tires have to carry 21,250# - and there are 4 tires, then each tire has to carry 5,313#.

If I assume the tires on your trailer are LT235/85R16 Load Range G, then the load carrying capacity is 3750# at 110psi.  

If I assume the trailer weighs 20K, ....... then each tire is carrying 4250#

Neither of these make sense, so I need to find out how many of those assumptions is incorrect.

---------- FOLLOW-UP ----------

QUESTION: The tire size is correct. The GVWR on the trailer says 16,000# but I believe that was before the trailer was finished adding living quarters but dont know yet. I assumed that with 4 horses at 1K# each and some extra lets say 2k more puts us at 22k#. I do use G rated tires bought from a reputable tire shop. I think my problem may be under inflation. I was wondering if they make a heavier rated tire for a 16" wheel? I will take the trailer and have it weighed in the near future.

Answer
Carl,

First, I think the GVW of the trailer is supposed to be when it is fully finished (and fully loaded) - unless the trailer was converted from an already finished unit.  

But if you think the trailer weighs 22K, then someone should have realized the tires are too small and fixed that before the trailer ever hit the road.

But I really think the trailer weighs in the neighborhood of 16K and that mean the tires carry 3400# - and that lines up nicely with the LR G tires.

BTW, I don't quite understand your comments about underinflation.  Aren't you using 110 psi?

I think our next step is to get the actual loads on the tires.  Anything else we could do is just based on speculation.