What is the Correct Tire Air Pressure For a ST205/75D15 Tire
What is the correct tire pressure for my trailer tires. Size is ST205 75 D15. Thanks
asked by: Bob
Special trailer (ST) tires should be inflated to the maximum air pressure that is stamped on the sidewall of the tire. It will be stamped with a designation of maximum load at a maximum psi.
For example, the Redline ST205/75-D15 Bias Ply Trailer Tire and Wheel, part # TW15BIAS5ON475, that you have referenced is a load range C tire. It has a maximum capacity of 1,820 pounds at 50 psi. That means the tire is capable of carrying up to 1,820 pounds of weight if you have it filled to the maximum air pressure of 50 psi. With maximum air pressure, the tires will perform and wear better, and will get better gas mileage.
The ST205/75D15 tire will usually be available in a load range B (4 ply rated) tire which is 1,480 lbs at 35 psi, a load range C (6 ply rated) which is 1,820 lbs at 50 psi, and a load range D (8 ply rated) tire which is 2,150 lbs at 65 psi.
I am including a couple of links to FAQ pages on trailer tires and trailer tire sizing.