Tire and Wheel Recommendations for a 37 Foot Dual Axle 5th Wheel Trailer with 235/85-16 Tires

Question:

I have a 37 foot fifth wheel trailer with LT 235/85R16 - Load range G tires Goodyear G614 RST - rated at 3750# @ 110psi. The trailer recommendation is to run 110psi inflation due to nearly 14,000 lb. trailer weight on 4 tires. My present rims 11 years old is rusting under the paint and am concerned that I should replace them before I have rim failure. Question: What is the difference between AM20750 and AM20768? What is the load and pressure rating of each? And which would you recommend for my trailer?

asked by: Larry R

Expert Reply:

The Dexstar Steel Spoke Trailer Wheel, # AM20750, uses 1/2 inch -20 bolts AND/OR 9/16 inch -18 bolts. It is rated for 3,750 pounds at 110 psi.

The Dexstar Steel Spoke Trailer Wheel, # AM20768, uses just 1/2 inch - 20 bolts. It has a capacity of 3,960 pounds at 110 psi.

The rest of the specs are the same for each. Both are 16 x 6 inch wide, have an 8 on 6-1/2 bolt pattern, and a pilot diameter of 4.9 inches.

The Dexstar Steel Spoke Trailer Wheel, # AM20750, would be the way to go for two axles with a total of 4 tires.

Make sure to use ST trailer tires. The ST in front of the tire sizes indicates Special Trailer. Trailer tires are designed with a thicker side wall to handle more vertical load. An LT is a light truck tire and light truck tires should not be used on trailers. The exception is if the LT comes at the END of the size then that would indicate it is appropriate for trailer use.

Some Load Range F tires actually have a higher capacity than some Load Range G tires. I recommend the Karrier ST235/85R16 Radial Trailer Tire, # AM10501. This is a Load Range F tire rated for 3,960 pounds at 95 psi. However, you will need to stay within the capacity of the rims at 3,750 pounds at 110 psi.

Trailer tires should always be inflated to the maximum psi listed on the tire to avoid excessive heat build up and failure. I have included a link to our FAQ articles on trailer tires and wheels.