Weight Capacity of 5th Wheel Trailer Tires Required Accounting for King Pin Weight in GVWR

Question:

My 5th wheel has a gross weight of 11,995 lbs. The tires supplied by the RV Mfg were West Lake ST225/75R15 LRE. It appears to me that each tire can carry 2830 lbs per tire for a total 11,320 lbs. Do you subtract off the hitch weight? Otherwise the math does not work, correct??

asked by: Dave C

Expert Reply:

Technically you do remove the tongue weight of the trailer from the tire load capacity for the GVWR. The tires only need to be rated for the weight that is actually on the tire, so the axles can even be rated slightly lower. This however is not normally the case. In most instances the axles and especially the tires are rated higher than the required capacity for the GVWR.

For 15 inch tires the load rating of E is the highest rating we carry. The Westlake ST225/75R15 Radial Trailer Tire - Load Range E # LHWL304 are rated for the 2,830 lbs you referenced as well as speeds up to 75 mph. They also come with the best warranty of 5 years with 2 years roadside assistance included.

If you are looking to change your tires, the Karrier ST225/75R15 Radial Trailer Tire - Load Range E # AM10303 which has the same load capacity would be another great option.

expert reply by: Jason S