Trailer tires, radial vs. bias ply

I think you will find most are going to G rated ST or E rated LT tires. I have run LT's on my 5W's for years with out issue. I currently have an 11K 5W 2017 with LT's. Ask at a good tire shop what they recommend. This is pretty general as what kind of unit and weights will help answer more.

I would stick with ST or LT radials at time of replacement.
Get tires rated to carry the full GVWR.

I understand from a number of sources that passenger car tires don't have the stiffness in the sidewalls to safely handle a travel trailer.

Bought a new Kit Companion in 1995. It came with made in the USA Goodyear Marathon radials. Original tires were still on it when we sold it in 2002.

Automotive radials (P rated) are not a good choice for a travel trailer. They don't have the side wall strength of an ST tire. Once you get into the 16" rim size LT tires with the correct weight capacities are a good choice. There are commercial 14" tires like the Hankook Radial RA08 that are not ST tires but will will fine with a higher LR than an ST tire. The Maxxis Bravo series is a non ST radial that would work. Finally, Goodyear's new Endurance ST tire is sounding pretty good.

P or LT or ST tires work fine on trailers when properly fitted to the trailers axle weight requirements.
....Many trailers (rv and non rv) come with P tires.
....Not many bias ply tires are made anymore as most trailers come with radials.
.... P tires aren't speed restricted like ST tires.
Hell before the tire industry gave us the infamous ST tire all we had were passenger tires on lighter trailers and light truck tires on our heavier trailers.

P tires (44-51 psi) on trailers with 3k-3.5k axles work great. Years back our passenger car tires had a 32 psi max pressure which wasn't enough pressure to hold the tires seated to the wheel on a heavier trailer. Tubeless tires would pop the beads with 100 percent air loss resulting in the tires coming off the wheel as the trailer was pulled around a corner or backing maneuvers.

Tell your bro this from fed regs regarding using a P tire on a trailer;

fed regs wrote:
per 49 CFR FMVSS safety regs 571.110

S4.2.2.2 When passenger car tires are installed on an MPV, truck, bus, or trailer, each tire's load rating is reduced by dividing it by 1.10 before determining, under S4.2.2.1, the sum of the maximum load ratings of the tires fitted to an axle.

Example; the P tire may have a 2201 lb capacity.....divide by 1.1.....the P tires actual capacity is now 2000 lbs.

If using a P tire on a lightweight trailer I would select a P tire with 10-15 percent reserve capacity above the trailers axle rating.

Heavier trailer above say 7k I would use a ST or LT tire.

https://rvingwithmarkpolk.com/2012/11/08/trailer-towing-st-tires-vs-lt-tires/

Learned some things here..

falconbrother wrote:
From what I can see most travel trailers come with bias ply tires. My brother switched his out for automotive radials and claims they pull better and that he has had none of the issues that he had with bias ply, like chunks of tread falling off and blowouts. Is it safe to put radial car tires on a travel trailer? What about the weight ranges, car/truck vs. travel trailer?

What brand are you looking at. I haven't seen anything but radials on any of the trailer we have loked at in the past 14 years. From Jayco to Coachmen.

but the tires still blow after 4 or 5 years. So far for me. 3 1/2 years is all I'm getting out of radial TT tires, and I take very good care of them.

I haven't seen a bias ply tire on any trailer since the 80's.
And there sure haven't been any of them at the RV shows.
But I can tell you from towing with both that the radials have a lot more stick, especially in the wet.

I put bias tires on my 6k weight trailer. They now have about 5000 mils on them they pull no different than the radials I had on it. The test will come when I see if they have the sidewall cracking issue I had on the radials.
Jesseannie