Can a B78-13ST Tire and an ST175/80-13 Tire be Used at the Same Time on a Trailer

Updated 07/25/2016 | Published 07/23/2016

Question:

This is in regards to trailer tires for boats. Considering lug nut spacing and tire ratings the same, could you have a B78-13ST tire on 1 side and a ST175/80D13 tire on the other? Thanks.

asked by: Tom

Expert Reply:

Tire size ST175/80D13 is the metric equivalent of a B78-13ST so you technically could have both sizes on the trailer at the same time. However, if the tires have different load ranges that would mean they also have different ply ratings. The ply rating difference and the tread pattern difference can lead to uneven tire wear and tracking problems. Ideally you will want to have all tires on the trailer the same.

I have included a link to the ST175/80-13 tires that we carry.

expert reply by: Michael H