Replacement Trailer Tire for an Old A78-13 Tire

Updated 04/23/2014 | Published 04/22/2014

Products Featured in This Question

Karrier KR03 ST175/80R13 Radial Trailer Tire - Load Range D

(2424)

$104.94

Karrier KR03 ST175/80R13 Radial Trailer Tire - Load Range C

(2424)

$97.70

Loadstar ST175/80D13 Bias Trailer Tire - Load Range B

(3942)

$69.22

Loadstar ST175/80D13 Bias Trailer Tire - Load Range C

(3942)

$89.14

Loadstar ST175/80D13 Bias Trailer Tire - Load Range D

(3942)

$91.22

Question:

What is the replacement size for A78-13St

asked by: Elaine

Expert Reply:

The metric equivalent of an A78-13 tire is a 175/80-13. This size is available in load range B, # AM1ST74, rated for 1,100 pounds at 35 psi.

It also comes in load range C, # AM1ST76 for bias ply or # AM10199 for radial, both rated for 1,360 pounds at 50 psi.

And there is also a load range D in this size, # AM1ST77, for bias ply and # AM10210 for a radial both rated for 1,610 pounds at 65 psi.

Radial tires run cooler and track better than bias ply tires but bias ply tires are better for off-road applications. I have included a link to our articles on tire sizes and trailer tires in general.