Car or truck tires on a trailer

[Tom_W]

Thanks for all the input. Trailer tires it is.

 

[Renze]

There's a lot of difference in trailer tires. At our company we sell trailers with the small 10" tires to get low floor heights. They bounce like idiots and are likely to get damaged when you hit a kerb stone. The bigger ones run much better, bounce less and pull lighter. The most popular tire for low deck trailers is something like the 185/65 R14, it has a 14 inch rim with a thin ring of rubber around it. http://www.doornwaard.nl/images/97_foto2.jpg
(the distance between rim bead and road surface is small) this gives the best stability on tandem and tri axle trailers, while maintaining enough rupture resistance when cornering.

 

[George2615]

I'm sure you could mount car or truck tires on your trailer but they may or may not be legal for use on a trailer. At local DOT stations here (usually they set up in rest areas on the highway) they have occassionally checked trailer tires to see if they actually are trailer tires. Call your local DMV to see what the requirements are for trailer tires in your state. Trailer tires are made differently than regular tires as Bird said. I would get load range E tires for your trailer, not C or D. I found two sites that describe why you should use ST tires on trailers. They are (Easternmarine.com and Thetirewarehouse.com) both give good answers.

 

[Joe1]

Tom:

I'm making an assumption here and it may be wrong. I'm assuming the trailer with the car tires probably had wheels from a passenger car and is possibly a home made trailer from junkyard parts.

A couple of things to keep in mind. A load range B tire has a 4 ply rating whereas a C is 6 ply and a load range E is a 10 ply tire. Simply replacing a 4 ply rated tire that came with a passenger car wheel rated for a 4 ply tire with a 10 ply rated tire will not give you the load rating shown on the "E" tire. You would have to go to 80 psi to achieve the full load range of the "E" tire, but you would still not have the full load range because your wheels were not designed for that much weight or that much tire pressure. The axle, wheels, bearings, springs and tires must all be designed for the "E" tire to get the full load capacity at maximum tire pressure. A load range E tire even on the correct wheel at 35 PSI will not have the same capacity as it would at 80 PSI.

I would recommend that someone that knows should check the wheels, and the rest of the trailer to determine the correct tires to be installed and the correct pressure. If you have a light weight trailer you would be wasting money going to an "E" tire if the trailer's Axle only needs Load Range "C" tires.

Just my opinion.

 

[Bird]

Just your opinion, Joe? Maybe a little more than that, because I know for a fact that you're right. In 1972, we made a trip to Alaska and I had an aunt and uncle who went, too. He had built his own slide-in camper for his half ton Chevy pickup, had done a real professional job, and was not overloaded. However, he decided (thought) it would be better to have 8 ply tires on the pickup instead of the 4 ply it originally came with, and he ran 50 psi in the tires. After several unexplained leaks, patches, a new tube, etc., one wheel actually split and the tire blew. Those wheels are just not made for that kind of air pressure. When I retired, I had a fifth-wheel travel trailer with two 3500 pound axles. But I got the trailer completely loaded out, including washer/dryer and generator and we were living in it. I found that I was running 7300 pounds on those axles and I ruined a couple of the original tires going to Alaska in 1990. I talked to the trailer manufacturer about the possibility of adding a leaf to the springs and going up one step on tires and was referred to Dexter Axle, so I sat down at the factory with the Dexter Axle guy and he also told me the wheels would not be safe with the heavier tires. Instead, they custom built me a pair of 5,200 pound axles, new tires, wheels, brakes, everything from the frame to the ground except that we kept the same shock absorbers.

 

[machmeter62]

Tom, I've been out of the tire business a few years, but I think what I'm about to say still holds true. There are two reasons to use ST (trailer) tires instead of P (car) or LT (light truck tires).
1) There's a slight difference in the chemical composition of the rubber used. The ST tires are built to withstand the ultraviolet rays of the sun a little better and resist "weather cracking".
2) As has been mentioned, with a tandem axle trailer, turning puts a considerable stress on the sidewalls and the ST tires are designed to handle it a little better.

Those were the facts from long ago. What I never actually experimented with myself, but have heard (and believe) is that you DO NOT want to use trailer tires on your car or pickup. But you CAN use car or pickup tires on your trailer. You'll probably have better luck; i.e., longer lasting tires on your trailer if you use the ST tires.

BIRD is absolutely correct on his analysis. The tires on any trailer used for towing, single or double axle, is subject to "squirming," even in tracking a straight line down the freeway, they are always "hunting a little bit," from side to side creating friction, which is turned to heat! Also, if the tire has aged, and operating at it's max weight/pressure, you maybe subject to a "blow-out!" If you are going to use the trailer only for short distances at low speeds, other type tires maybe okay? I learned the hard way!! Spend the money and be "safe" with trailer tires, and have "peace of mind!"

 

[Joe1]

Bird:

I added: "Just my opinion" because I'm not an expert and learned like most from reading and observing and doing and making my own mistakes.

Also, if I'm wrong it will hopefully not generate 50 "experts" telling me so.

Joe

 

[kenmac]

I went with the 8 ply trailer tires for my trailer. I had put 2 sets of car tires on that trailer that kept dry rotting. I hope I have better luck with the 8 ply trailer tires.

 

[Joe1]

Depending on how the tires are stored, i.e. outside, exposed to sunlight and smog, etc. the tires will still be good for only 5 - 7 years before they should be replaced. They may have plenty of tread, but they will start to "check" as the ultraviolet rays start to break them down. I replaced a set of RV tires for just that reason. The tread looked great, but they were unsafe. Keeping the sun off them will help, but they only last so long.

Hopefully, the wheels match your 8 ply Load range "D" tires.

I had a cousin that lived in a double wide mobilehome. He took the wheels and 8 ply tires and used them on his 1/2 ton Chevrolet. The wheels and bolt patterns matched perfectly. I never did figure out how well that worked or how long they lasted.

Good luck.

 

[Mahana79]

Here is my $.02

On my multi axle trailer i will only run Bias Ply ST tires. im my time in the tire industury i saw tons of radial ST tires with seperated belts. a bias ply tire is better suited to absord the flex that occures when making a turn call "tire scrub" i have a 32' triple axle and got into a bind in a parking lot one day. had about 14,000# on it and had to go back out the way i came in Everything was correct, Load range E tires. 80 PSI correct wheel for the tira and all that hoopla. had enough tire scrub and weight that it actually pulled the bead away from the wheel on two of the tires. that type of flex will pull the steel belts apart in a radial tire. In our off road buggies we run bias tires for that reason on the rocks. the bias tires will flex and wrap around the rocks where the radials wont.

so for me Bias Ply trailer tires all the way