Can 175/80D13 Tires of C and D Load Ratings be Mixed on a Trailer

Updated 08/27/2014 | Published 08/26/2014

Products Featured in This Question

Loadstar ST175/80D13 Bias Trailer Tire with 13" Galvanized Wheel - 5 on 4-1/2 - Load Range C

(7209)

$120.99

Karrier ST175/80R13 Radial Trailer Tire with 13" White Wheel - 5 on 4-1/2 - Load Range D

(1556)

$147.57

Question:

I have a Tahoe tandem axle trailer with two Loadstar 175/80 D13 tires load range C AM35160 and would like to buy two new Loadstar 175/80 D13 tires load range D. Your technical specs show both tires have a section width of 6.6inch and an outer dia. of 24. Is there a problem with using the load range D with C. Same axle or same side or in front or behind. Is the tread width the same? My current class C have a tread width of 5. Is the class D the same? Is it a problem if it is not? Thanks for you time.

asked by: Larry R

Expert Reply:

The two 175/80D13 tires/wheels you referenced, Load Range C # AM3S160 and Load Range D # AM31985, will both have an overall diameter of approximately 24-inches, give or take a small fraction. The Load Range B and C tires/wheels will share a 6.6-inch section width while a D-range will have a section width of 7-inches.

We do not recommend mixing tire types, sizes or load ranges but for example in the case of a spare tire that will be used for only a short distance (and at or below its speed rating of 65-mph) it is not an absolute disaster to have differently-rated tires on the trailer for a brief period. I do not recommend having different tires in use on the trailer on an ongoing basis.

Different load ranges will have different psi pressure requirements and will deliver different weight capacities. They may also have noticeably different ride characteristics depending on their age, tread wear and ambient temperature conditions and on the trailer load. If you had to mix tires it would be better to have them be the same on any given axle and have the axle with the higher-rated tires be the one bearing the greater portion of the trailer load.

Tread width can vary very slightly between brands of the same size tire or between radial and bias types of the same size but these differences will be subtle since they all have to meet the overall width specification, in your case 175 mm.

expert reply by: Adam R