Quote:
Originally Posted by skids
Also, I question if rated loading for single at 2040 lbs @ 65psi and dual 1820 @ 65psi makes sense? Dual is when two tires are mounted side by side much like on the rear of dually trucks.
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As the standard is written, tires fitted to RV trailers MUST provide a load capacity equal to the maximum load of the vehicle certified axle (s). That's 1750# of load capacity for each end of a 3500# axle. In years past an owner could expect to see those 3500# axles fitted with tires providing 1760#.
Within the same standard the vehicle manufacturers are directed to use tires that are appropriate for that vehicle. For most TTs that means they can use ST, LT or P tires. Once their selection is made and displayed on the vehicle certification label, it becomes the minimum standard for
that vehicle.
Trailer axles are hardly ever balance equally and one end can be carrying substantially more weight than the tire can support. The tire degrades rapidly and fails.
Because NHTSA failed (again) in 2010 to change the rules to something that would provide tire load capacity reserves for RV trailer tire fitments, RVIA stepped-in. RVIA's membership comprises about 98% of the manufacturers of RV trailers. Their recommendation to the membership was to insure original equipment tires provide a minimum of 10% in load capacity reserves above vehicle certified axle maximum loads.
For today's 3500# axles, the minimum load capacity is 1925#. That makes the tire providing 2040# of load capacity a good choice. The tire industry are quick learners and that's why the ST205/75R14 tires are now produced with a LRD load capacity.