Tires - Car vs Trailer

[Chris]

On our road trip with the popup we blew a trailer tire in the middle of nowhere Wyoming. Not wanting to risk being stranded we bought the 1st one we could find. I never heard of HI-RUN brand but that's now our spare. The guy that sold it to us said we're running car tires on the trailer which he said was 5 ply vs 6 ply that should be on the trailer. Was I handed a line? It seems to me a car tire would get more abuse than a trailer tire assuming they're both the same size.

Oh yeah, the one that blew pretty much disintegrated and lost most of the tread, the guy told us it wasn't a retread but it sure looked like it was to me.

[ColoJeeper]

I don't know a lot about the difference, but can't imagine there being a problem on a popup trailer unless you filled the water tank with lead. My guess is that your tire was underinflated and just got way too hot and came apart.

[Chris]

My popup isn't very heavy but it was 90+ all the time and we were covering a lot of miles. The tire pressure was good, checked it daily knowing we'd be covering a lot of miles.

[Patrolman]

My understanding was that trailer tires have less rolling resistance, less traction (no need for steering), and stiffer side walls for heavier loads. Of course, for a pop up trailer this probably doesn't apply. A car tire trailer is probably just fine. It is completely possible that the tire went low and you didn't know it before it blew out. I had one go low and it didn't blow out, but popped the bead. I pulled over right away though and saved it. I imagine you are fine with what you have, particularly since it is the spare.

[CS79bronco]

I have a friend who has blown 2 of 4 Hankook tires recently on his car hauler, 3rd one has begun to come apart in the tread. You can see the tread "squiggle" as you roll the tire by hand. These are trailer tires, load range D, not very old. Since I recently bought a hauler to haul a Bronco on, I have done lots of reading on tires. There is a distinctive difference in the construction of trailer tires & car/truck tires. Trailer mfg's & tire mfg's both recommend using trailer tires on trailers rather than auto tires for several reasons. Good enough for me.

[scout man]

Yea, I blew a tire on a horse trailer and was told by the walmart tire people that they legally couldnt install a car tire on a trailer for me. Something about the sidewall thickness. It didnt make a lot of sense to me either, but I dont think you were lied to.

[gm4x4lover]

There are alot of differences in ST (special trailer) tires to car tires. Mostly because the trailer doesnt have a dampaning style spring but rather a load style spring. So the bouncing takes a huge toll on the car tire. LT (Light truck) tires really arent designed for it either but you can put enough air in the LT (usually 50psi to 80 psi) tire to make a difference. Also car tires are only tested at max load carrying capacity 10% of the time and 60% the rest of the time. LT and ST tires are tested 100% of the time at max load. Because of this if you compare a P235/75r15 tire to a LT235/75r15 the P rated tire holds more weight because it takes longer to fail due to it being tested a lower load amount compared to the LT tire. Trailer tires also carry alot more weight than the truck tires in the same size even with the same amount of psi. A LT235/85r16 tire holds 3095lbs where as a ST235/85r16 36??lbs. This is due to the different style side construction. The ST is designed for minimal cornering needs and builds less heat directly. A bias ply tire usually hold less weight with more air pressure than a radial of the same size with a lower ply rating. Also you have to realize that modern tires are almost all the same when it comes to the amount of plys in the tires. A 10ply doesnt have 10plys. It usually will have a 2-3ply side wall and a 5 ply tread. A P-metric (passanger rated), or a 4 ply tire will also have 2-3 ply side wall and a 5 ply tread. The LT and ST tires are designed to carry a higher psi rating. Old tires back in the day Physically had the higher ply counts so they could hold the higher pressure. Thats the difference in a nut shell.

[dannanw]

For a pop up your fine. My yard service trailer is an old pop up and has had car tires for many years. A heavyweight trailer is another story. All the above named reasons are true, I used to work in two different tire shops and when mounting two you/anyone can feel the difference.

[Chris]

Thanks everyone!