Community Forums

Rotaxxx · 05-11-2013, 04:00 PM

My fifth wheel has a max weight of 7,200lbs, right now it has 205/75r15 tires on it that are badly cracked so I need new ones. I have a dodge 3/4 ton diesel that I tow the trailer with, it sits high and my trailer goes down the road with the front higher than the rear. It's not terrible, but it's noticeable. Any who in the search for tires I have found trailer tires in the 205/75R15 but they are all Chinese made. So I thought I would upgrade to a 235/75R15 tire, it's a little taller and would help with my trailer sitting level when towing it.

Long story short, I found some Goodyear Wrangler Radial in 235/75R15 and bought them. link

The website I ordered them from said they were a LT tire but it's sized as a P235/75R15. So it's a passenger car tire right?
They are rated at 2020lbs a tire at 35psi. Is this a good replacement tire?
Please help a tire newbie! Thanks all!

bradufault · 05-11-2013, 04:44 PM

If the tire stats with a "P" it's not a truck tire. There is a very good article in Trailer Life, June 2013; about trailer tires.

amxpress · 05-11-2013, 06:57 PM

If the tires are designated "P", they are passenger car tires and should not be used on your trailer. Their sidewalls are not designed to handle the stress placed on them by a trailer. Your best bet is to find a quality ST tire. Maxxis seems to be the best of the ST tires. Other ST tires that have been redesigned recently are Hercules, Tow Master, and the newer Goodyear Marathons.
Be sure to have them balanced.
Good luck.

Ray,IN · 05-11-2013, 08:13 PM

Those tires are not acceptable for trailer tires. You've already bought them, which makes my next statement hard to swallow. Measure the distance between axles, and from the axle centerline to the bottom of the trailer. If you have room I would switch to 16" tires and rims, both to raise the trailer and insure you have a comfort margin with tire load.
I raised my 5er by inserting 1/5" square tubing between the axle and springs. Together with larger diameter tires and the 1.5" spacers my truck and trailer sat level when hooked up.

FastEagle · 05-12-2013, 07:25 PM

Quote:

Originally Posted by Rotaxxx

My fifth wheel has a max weight of 7,200lbs, right now it has 205/75r15 tires on it that are badly cracked so I need new ones. I have a dodge 3/4 ton diesel that I tow the trailer with, it sits high and my trailer goes down the road with the front higher than the rear. It's not terrible, but it's noticeable. Any who in the search for tires I have found trailer tires in the 205/75R15 but they are all Chinese made. So I thought I would upgrade to a 235/75R15 tire, it's a little taller and would help with my trailer sitting level when towing it.

Long story short, I found some Goodyear Wrangler Radial in 235/75R15 and bought them. link

The website I ordered them from said they were a LT tire but it's sized as a P235/75R15. So it's a passenger car tire right?
They are rated at 2020lbs a tire at 35psi. Is this a good replacement tire?
Please help a tire newbie! Thanks all!

When Passenger tires are fitted to trailer axles - any trailer - their load capacity rating MUST be devalued. The actual procedure is to divide maximum load capacity of the tire to be used by 1.1.

In your case that would be 2020/1.1 = 1836 total load capacity per tire.

Passenger tires are not always suitable for trailer use. There are always exceptions and many Airstream owners do use them on trailers very close to your weight class. However, they normally use XL - Extra Load - tires that normally require more air pressure.

Rim compatibility is curtail to proper fitment.

FastEagle

Rotaxxx · 05-12-2013, 07:28 PM

Thanks for the replies guys. The tires I got have the same ply rating as the trailer tires, and a higher payload so I don't see why the wouldn't work. I think I Will give them a try and see how they work out.

bradufault · 05-12-2013, 07:34 PM

No offense but I think your making mistake. You should only be using "ST" or "LT" safety
should always over ride all decision.

JIMNLIN · 05-12-2013, 08:02 PM

Quote:

They are rated at 2020lbs a tire at 35psi. Is this a good replacement tire?
Please help a tire newbie! Thanks all!

The clicky link is to a All terrain type tread P235/75-15 at only 35 psi and is a poor choice for your tandem axle 5th wheel trailer. Even the tread design isn't a good choice for a highway trailer.

TheGoodyear Wrangler HT LT235/75-15 C at 50 psi and 1985 lbs of capacity and is tops for any tire for a trailer that size. I would use this tire over any ST tire. The C load range is a 6 ply rated tire and has much heavier/thicker plies in the sidewall than a P tire.

The P is a one or two ply very thin sidewall and a very low 35 psi. As FastEagle says its 2020 lbs capacity is to be derated to 1838 per fed regulations when a P car tire is used on a truck or trailer. A 35 psi is a very low pressure. I've seen and have personally had P tires on multi axle trailers unseat the beads while side scrubbing (sliding sideways) on sharp turns around a corner.

If you go with the car tires keep them pumped to the max.