4.80-12 Load Range C Tires Run At 90 PSI?

Question:

I know you have answered this previously, but I have a small landscaping trailer with 4.80-12 Load Range C, 2 ply tires. 65 - 90 psi sounds extreme for these tires as I had tractor trailers that only required 90 psi. Does this rule hold true for these tires?

asked by: Steve

Expert Reply:

The Taskmaster 4.80-12 Bias Trailer Tire with 12" White Wheel - 5 on 4-1/2 - Load Range C # AM30660 are similar to what you describe. The psi level on trailer tires is higher than most other tires. They are made differently and that 90 lb psi is actually what they are to be run at when filled cold. As they heat up from running, they will get higher yet. This rating even though it is listed as max psi is what they are to be constantly run at...there isn't a minimum.

Running the trailer tires inflated to under that psi could cause a blow out as the tires are not running as intended. Improper inflation is the top cause of trailer tire malfunction. Trailer tires have a stronger sidewall than most other tires and require this higher psi for proper tread wear and heat dissipation.

expert reply by: Jason S