Trailer Tire Load Ranges and Inflation Pressure on 2012 Coachman Catalina 28bh

Question:

The tires that can on the vehicle are st205/75r15 D load The previous owner replaced 2 of the tires with provider st205/75r15 C load tires. I just bought two Kenda karrier st205/75r15 D class tires to replace the two original D class tires that are still on the trailer. I will have two C and two D tires on the travel trailer. Should I air the C to 50 psi and the D to 65 psi or put all 4 tires at 50 psi?

asked by: Landon A

Expert Reply:

Trailer tires should always be inflated to the maximum cold psi pressure rating shown on the tire sidewall. Only when fully inflated can a trailer tire deliver its rated weight-carrying capacity.

That said, it is not a good idea to mix tires on a trailer, neither sizes nor load range ratings. The lower-rated tires will run hotter than the higher-rated ones and could be more prone to failure.

Heat is the worst enemy of a trailer tire. The 3 most common causes for excess heat are incorrect inflation, driving faster than the tire's rating allows or overloading the tire beyond its weight limit. You can help avoid heat-related tire failure by always inflating to the correct cold psi pressure, observing the tire speed rating and staying within its weight capacity.

expert reply by: Adam R