Tires Upgrade

jjbrown6818 wrote:
A little background. I have a 40 foot, 2009 Montana 5th wheel. The placard on the side says the GVWR is 15600+ and the tires that are suppose to be used are shown to be 235/80R16 Load Range E 10 ply tire. I have had the trailer weighed and it is anywhere from 11,000 to 13,500 pounds. I say any where because I have had it weighed several times over the last three years. I have blown several tires in the last few years. After many phone calls to many tire gurus and talking with Drexel Axle people I have come to the conclusion that I have to upgrade my tires to Load Range F 12 ply. Those tires are 235/85R16. This means upgrading the wheels also since the ones I have will only allow air pressure up to 80 pounds and the Load Range F require 95 pounds of pressure.

There is no scuffing of the tires and it is suggested that there is not an alignment problem. Do you know how many trailer axle alignment businesses are out there? I haven't been able to find any very close to my location. After discussions with Drexel Axle and several tire dealers, they don't think I have an alignment problem since no specific tire or tire location fails.

Basically the question is.... am I going down the right road? I have had suggestions of going to Load Range G 16 inch tires requiring 110 pounds of pressure. It has also been suggested that I go to a 19.5 tire. The G 16 and the 19.5 tires are 14 ply.

Please let me know. I am going to make the change soon and the cost can be costly.

So you are caught in a Montana bear trap. Crummy OEM tires that are for delivery and show only!

If you are going to buy wheels, then buy 17.5 rims and 215/75R17.5 LRH tires rated 4805 each. They will be very close to the same diameter, slightly smaller actually. I think that you will have a problem finding 19.5 rims with zero offset and tires that are the correct diameter. Going to a load range F ST is still a ST problematic solution, and you will be wishing you installed commercial grade tires and the correct rims. I would not waste time and money on 16 LRG tires like GY G614's or Sailun, as you still have to buy rims for them.

Chris