Metric Tire Size to Replace B78-13ST Boat Trailer Tire

Updated 10/25/2017 | Published 10/24/2017

Question:

what tire will replace a B 78 - 13ST

asked by: Andy

Expert Reply:

A tire of size B78-13ST can be replaced with the metric trailer tire size ST175/80-13 which has the same overall diameter of approximately 24-inches when mounted and inflated. Both of these tire sizes will fit on a 13-inch rim with widths of either 4-1/2-, 5- or 5-1/2-inches.

We offer ST175/80-13 tires in three load ranges, B, C, and D, which have weight ratings of 1100-, 1360- and 1610-lbs, respectively. All tires and wheel/tire combination products in this size are displayed on the linked page.

In addition to varying weight load ratings these tires also have differing speed ratings. If we do not indicate a specific speed rating in the tire specs this means it is rated for 65-mph.

Special trailer tires should always be inflated to their maximum rated cold tire pressure as indicated on the sidewall. It is never appropriate to under- or over-inflate a trailer tire for any reason.

The two linked articles may be of help to you as you make your selection.

expert reply by: Adam R