Tires on a motor home/van/truck/etc with tires at the corners operate in a completely different environment than a trailer with tires in the center of a tall/heavy vehicle that scrub sideways as it rolls around the corners. Goodyear and Carlisle recommend max sidewall pressures. In fact its part of Carlisle tire warranty.
rvsafety.com
Tire Load and Inflation Ratings
Note: Towable – Travel Trailer/ 5th Wheel owners Due to the severe use conditions experienced by tires when axles are very close together – tire industry experts recommend maximum (sidewall) inflation pressure for towable tires unless this causes a sever over-inflation situation (20psi+), often referred to as the ‘basketball effect’. If this is your situation allow a 10 – 15psi safety margin above the minimum required inflation pressure.
And Tireman9 one of our tire engineers also recommends max sidewall pressures says; from rvtiresafety.com his online tire blog;
"The manufacturers do not take into consideration the side to side unbalance, as to do so would require them to provide larger (more expensive) tires. The other thing RV industry does not take into consideration is the forces to the tire structure due to running close axle spacing. Engineering analysis shows that when turning corners the forces trying to tear the tire apart can be over 20% higher in multi-axle applications than with tires at the corners of the vehicle.
The only options for the trailer owner are to up-size the tires (if there is room) or up-rate and increase inflation (if a higher Load Range tire and stronger wheels are available). Lacking the above being sure to run the tire at the inflation shown on the sidewall (i.e. max) will slightly decrease but not eliminate the overload forces.