Difference Between a P155/80R13 and a ST175/80D13 Tire

Question:

I need to know the difference between the 2 tires for a trailer . No one carries the P155/80R13 any more and I need help deciding what tire to get for my trailer I need to get 4 tires or tires and rims .

asked by: Missy

Expert Reply:

I have an answer for you to clear of some of the differences. If you have the tire size of P155/80R13, the "P" stands for passenger car tire and the "R" stands for radial tire. The radial means the way the steel cords/plys are layed in the rubber. With the ST175/80D13 Tire like the # AM1ST77, the "ST" stands for special trailer tire and is only compatible with trailers. The "D" stands for diagonal pattern. We do sell a similar radial version of the ST175/80D13 as tire # AM31991. This wheel comes with the same.

As far as the size, your P155/80R13 tires are a bit smaller than the ST175/80D13 tires. While the first measures 22.8" in diameter and 6.1 inches wide, the second measures 24" in diameter and 6.9 inches wide. In order to make sure that the tires are compatible with your current setup, I recommend making sure you have proper fender clearance and space on your current wheels.

Technically, you can use special trailer tires for passenger tire applications as long as long as the weight ratings of the tires are compatible. However, the biggest issue you can encounter is the tire placement. Trailer wheels are designed to have 0 offset, so they tend to have even tread wear to accommodate heavier loads.

expert reply by: Bob C