Recommended PSI for 12x4 Tires

Question:

how much should the tires be inflated at 12by 4 size ?

asked by: Donald S

Expert Reply:

It is recommended that tires always be inflated to the max psi, which should be listed on the sidewall of the tire. The psi ratings for two tires of the same size will differ based on each tire's load range. For instance, a Kenda 4.80-12 tire, such as Item # AM30670, is a load range C tire with a capacity of 990 lbs at 90 psi. However, the same size tire at load range B, such as Item # AM30590, has a capacity of 785 lbs at 60 psi. Different tire manufacturers may also have different psi ratings even for the same tire size and load range, so it's always best to go by the psi rating listed on the tire itself.

Also note that tires should never be over-inflated or under-inflated. Inflating tires to a lower air pressure than the maximum reduces the amount of weight that the tire can handle to an unknown amount, which can cause the tire to fail if a heavier load is placed on the trailer. Tires at maximum air pressure also perform and wear best (plus, you'll get better gas mileage). Over-inflating or under-inflating a tire also affects the way the tire wears over time.

The psi should be measured when the tire is cold—usually, first thing in the day is a good time. I've attached an article on trailer tires for you as well as a video about one of the 12x4 tires listed above.

expert reply by: Amber S