Comparing Two Tires of the Same Size For Spare Tire Use

Updated 07/09/2019 | Published 07/07/2019

Question:

Hi, My boat trailer came with a pair of Load Star DOT K3B5 U12 4.80-12 Load Range C tires. A few years ago I bought a spare tire that’s a Load Star DOT 2QB5 U12 4.80-12 Load Range C tire. The only visible difference is a different style rim and the stock tires say “High Speed.” Can you please tell me whether the spare is compatible and if there are any other differences? Thanks!

asked by: Dominic

Expert Reply:

When comparing two tires, what really matters is the size, bolt pattern of the wheel, speed rating and load range are the same. The DOT code is a date of manufacturer code so that isn't going to matter as much.

If both the stock and spare tire are 4.80-12 Load Range C tires then they are the same size so there will not be a difference there. You want to make sure both wheels have the same bolt pattern to fit the trailer. The only Loadstar 4.80-12 Bias Trailer Tire we carry is part # AM30670 which is a 5 on 4-1/2 bolt pattern (5 bolts) with a 65 MPH speed rating so that is most likely what your spare tire is but you want to make sure they are both the same.

Some tires do have a speed rating on them with a letter code. If you do not see a letter on the spare tire that means it is rated for 65 MPH so you do not want to exceed that speed.

expert reply by: Heather A