Tire inflation

avvidclif1 wrote:
There is enough tire expertise on this group that they should be able to design the PERFECT trailer tire. If only the mfgs and engineers would listen to the pros.

Its not that the manufacturars and engineers of tires are making bad tires. The original design is good and the pressure advices of car makers is to give as much possible reserve so as high as possible pressure for the conditions , for savety and fuel saving.

But then if the to goal declared means the Economy ask it, they go lowering their standards.

That is for instance for traveltrailers and 5th wheelers with lower speed then for cars, they suddenly allow themselfes to go to the edges of what is save. This means ST tires with about 18% more maximum load then a comparable LT tire , yust because they wont get damaged at 65m/h to their calculations.
At that more deflection so lesser fuel saving and a bit more load or more speed, or pressure drop and the tire is in the danger sone.

But what is written about always keeping "maximum pressure" is not always needed, there are exeptions.
for instance on Airstream forum I once reacted for TT with 2 axles 4 tires ST E-load so 80 psi. With all the reserves added for savety and reduction of maximum load only came to about 50 psi.

Also for the Ford Explorer ( you know from the Ford/Firestone affaire with more then 100 people died most because of roll over accident by blowing rear tire), the 26 psi appeared to be to low, but the later chanched to 30 psi apeared to be enaugh to give no damage to the tire.
Wilber1 writes 44 psi using , and probably has comparable tires and GVWR/GAWR as that Ford Explorer so most likely is completely save too at lower pressure , for instance 35 psi.

So best is still to calculate it with as much possible reserve without bumping and then if pressure even is a bit above AT-pressure , no problemm .