sh410 wrote:
@ FE or ERS
I have noticed that on many TT that use 3500# axles that they are fited with ST205/75R15 Load range C tires rated at 1760 at 50#Psi. That gives each axle a safety margin of 20# of load at max weight.
According to the load & inflation tables in order to have the recommended safety margin of 15% a better tire would be a ST205/75R15 Load range D tires at 2150# at 65#Psi and a rims rated for 65# which would give a safety margin of 4300# a 3500# axle or a 23% safety margin.
Could you please remark on the above?
I think you mean they come with ST205/75R14 Load range C tires rated at 1760 @50 psi. The ST205/75R15 Load Range C are 1820 pounds at 50 psi. Not really enough margin. You are right about using the ST205/75R15 Load Range D. Good choice. Another one of the same load capacity is the ST225/75R15 Load range C.
Just keep in mind, there is a difference in diameter between the ST205/75R14, the ST205/75R15, and the ST225/75R15. You have to check wheel well clearances, clearance between the tires if you have a multiaxle trailer, and consider the ramifications of altering the ride height.
