Tuesday, November 28, 2023


RV Tire Safety: Should ST tires be outlawed?

with RV tire expert Roger Marble

A post on an RV forum caught my eye:
“In 2014, when I bought my RV trailer, I immediately went to Discount Tire for 6 Michelin XPS Rib truck tires. I don’t baby them, I barely pay any attention to them, they’ve never been at 80 psi, and they have been wearing fine for 5 years. Been all over the U.S. with no issues. Yet I see new trailers coming into the dealership where I work with blown tires just coming from Indiana. Chinese bombs need to be outlawed.”

My response:
It’s unlikely they will be outlawed given the price sensitivity in the RV market. Unfortunately, many folks buy when the quoted price is just a monthly amount that is so low they will always be “underwater” on their purchase. The RV industry seems to only focus on making the sale. As long as it feels it can only make the sale by offering the lowest possible price, the industry will fight tooth and nail to not have to spend an extra $100 on a set of tires that can provide better durability.

In 2000, after the Ford Explorer recall, both passenger and LT-type tires were forced to meet newer, tougher quality and durability standards as required by the “TREAD Act.” But I believe that because of pressure from the RV industry, ST-type tire requirements were excluded from the new requirements as complying would have increased the cost to the RV company a few bucks and they simply didn’t feel they could stay in business if they had to increase their prices.

So, we are stuck with tires built to 1970 quality and durability levels.

IMO, until or unless the RV community in large numbers demands an improvement in the tire quality with an update and upgrade in the performance standards required by DOT, there will only be improvements on a small number of models that offer ST tires with more Reserve Load or offer actual LT tires. How many RV owners have made the minimal effort of filing a complaint on a tire failure to NHTSA? Or written a letter to the  Administrator of NHTSA? Here’s the address: U.S. Department of Transportation, 1200 New Jersey Avenue SE,  Washington, DC 20590.

When was the last time you heard someone not ask about buying tires at the lowest price? Or walking away from a sale if the dealer didn’t provide better tires as original equipment? Or the dealer didn’t offer a multi-year warranty on tires that came on the RV?

A review of some comments on this forum shows the truth in what I am saying. The new Goodyear Endurance seems to be providing a significant improvement in tire durability for ST-type tires, but we see several people stating they are not willing to pay the price.

If you are only willing to pay Harbor Freight prices for your tools, why would you expect SK, Milwaukee, Proto or MATCO quality?

From day one, ST-type tires were introduced as a low-cost option to higher-cost Light Truck-type tires when comparing pounds load capacity per dollar cost. We also had the 55 mph national speed limit, so offering tires with a 65 mph max wasn’t a deal breaker.


Read more from Roger Marble on his blog at RVtiresafety.net.



Roger Marble
Roger Marblehttp://www.RVTireSafety.net
Retired Tire Design and Forensic Engineer w/50+ years of experience. Currently has Class-C RV. Previous Truck Camper, Winny Brave, Class-C & 23'TT. Also towed race car w/ 23' open trailer and in 26' Closed trailer. While racing he set lap records at 6 different tracks racing from Lime Rock CT to Riverside CA and Daytona to Mosport Canada. Gives RV and Genealogy Seminars for FMCA across the USA. Taught vehicle handling to local Police Depts



0 0 votes
Article Rating
Subscribe to comments
Notify of

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Oldest Most Voted
Inline Feedbacks
View all comments

arlene (@guest_85345)
3 years ago

good article with useful info; a few questions however: where do you find the designations being refereed to in this article? for example the LT and SP, where do you find that? and also the H, D, etc rating is found where?

Dave (@guest_85344)
3 years ago

Why can’t I find a G-rated LT tire?

DLT (@guest_57353)
4 years ago

Here is my experience. It is similar to other comments.
I had no issues with ST tires on my first two tag along campers. I was a newby and was not aware of axle ratings and tire ratings but did keep the tires inflated to their max rating.
My next camper was a 5th wheel and I experienced 3 tire failures in 3 years. At that time I started investigating ST tire failures. My biggest take away is that they are rated only to tow at 65 mph and with the extreme summer heat down here in the south a tire that is stressed close to it’s maximum rating will not stand up to the heat. After further investigation I was able to upgrade from a D rated tire to an E rated tire. Adding that additional 15 pounds of air solved my problem.
IMHO the biggest issue with ST rated tires is that manufacturers put on the absolute cheapest tire they can to keep costs down. That typically involves using a lower load rated tire when a higher rated tire would offer better protection.
I just purchased a small dual axle camper that has a maximum weight of around 5400#. The previous owner installed 4 new tires with a D weight rating versus the replaced C weight rated tires. Those 4 tires have an 8000 pound rating on a 5400# camper. On our first trip to Myrtle Beach several months ago I checked the tires on a stop. Cool as a cucumber.
So in summation: The problem with most ST tires is that they are typically undersized from a weight rating safety margin. If you must run ST tires run a higher rated tire if possible and keep them inflated to their maximum rated psi. If you can upgrade to LT tires that is a great option. That was not an option on my 5th wheel since it used 15″ rims.

bisonwings (@guest_56739)
4 years ago

There are a lot of variables to consider when selecting trailer tires. Price is usually a major consideration but there is a hidden cost that should be included in our purchase decision. That cost is the damage potential of an inadequate tire selection. The sides of most RV’s are thin, light weight and flimsy. A high speed tread separation can destroy not only the tire well but the side of your coach too. If you check out the cost and down time of replacing your RVs side wall it puts a whole new light on tire selection.
My Excel 5th wheel came with GY 17.5” commercial ST tires. They are H rated (4,805 lbs @ 125psi). The gross weight of our trailer is 18,700 pounds. Subtracting the 3,700 pound pin weight means we have a safety net of 4220 pounds for the trailer or 1055 pounds for each tire.
On every other RV trailer I have owned the manufacturer placed a tire that was maxed out at full gross weight minus the hitch weight. Those were all 16” tires and there were no options to get a higher load range tire and the maximum pressure was 80 psi.
I am meticulous about keeping my tire pressure at the correct levels and weighing each tire to determine the actual load and I have still experienced tire issues with 16” tires. It seems that one of the primary issues with this size tire is the height of the sidewall. With only 80 psi and the lower ply rating there is just too much flexibility in the sidewalls which leads to the tire breaking down. Even though the cost of replacing 4 tires and wheels can run $300-500 or more it’s still a bargain compared to what the cost of rebuilding a sidewall would be.

Gary (@guest_56222)
4 years ago

If LT stands for light truck, what does ST stand for? (besides sh***y tire)

RV Staff
4 years ago
Reply to  Gary

Hi, Gary. A quick reply is: “ST” stands for “Special Trailer” — tires to be used only on trailer axle positions. I’ll let Roger Marble explain further, if he is so inclined. In the meantime, here is a link to his posts at RVtravel.com: https://www.rvtravel.com/?s=Roger+Marble
Or you can search his blog at RVtiresafety.net: http://www.rvtiresafety.net/
Diane at RVtravel.com

Roger Marble (@guest_56413)
4 years ago
Reply to  Gary

Officially “Special Trailer”

Lee (@guest_55902)
4 years ago

Well, as you (and others) keep pointing out, tires that are underinflated, overloaded, and over-sped WILL fail, sometimes quite spectacularly… As will anything that is misused. If you constantly run you engine above the redline it will fail. That’s an operator problem, not an equipment problem.

I have had a utility trailer, pop-up, and now a TT, all with ST tires and no failures, even from the so called ‘China bombs’. But then again, I don’t overload my trailers, I maintain proper tire pressure, and I don’t pull at speeds over 60 mph.

However, as in all things, YMMV…

C Donald Butler (@guest_55896)
4 years ago

After 3 years I bought Goodyear G14s now I have peace of mind .

TravelingMan (@guest_55873)
4 years ago

Sorry to say that it’s not just tires….I’m not exactly sure how they call RV’s “road worthy” to begin with. We bought our unit in 2015 (2014 model year). Our dry stickers were wrong. The axles, springs and tires were undersized. The 2.5″ electric brakes were illegally undersized and could not stop our 42′ rig. The bushings in the springs were cheap plastic. The pin box is nortorious for weld cracks. The frame is so weak that stress cracks are in the slide openings and side walls. The roof lasted 4 years. The slide seals are in need of replacement (slides have to be removed at a cost of $1200 each). And the list goes on. It doesn’t matter if the rig is $15,000 or $150,000. UNTIL enough people get fed up and demand action from legislators, the RV industry will continue to build more and more junk and continue to rip uneducated consumers off. If you doubt this as an isolated case, buy a rig and get in line at a repair shop. You will wait for months to get anything fixed and again, you’ll be taken to the cleaners. Since we have owned our rig, we have paid for it twice. That’s just in 4 years! I try to make most of the repairs myself to save money where I can. We are in Shipshewana now getting $15,000 worth of work done now. I am meticulous with maintenance. I have been in maintenance and construction for about 40 years. After this latest repair, we will be getting that new roof from someone in another state who actually knows how to install one. That will be another $9,000. Don’t buy an RV unless you have an endless bank account to support it. We are full timers and had we known what to expect, we would have opted for another path. We’re too deep now to go back. Save yourself!

Back to tires…The tires can come from any country but before laying blame on the manufacturer, when was the last time you weighed your rig by tire and pin box? How many folks bought the RV from a company that specializes in cheap? What tires, springs axles or brakes came on the rig? Did anyone bother to look at what they were before they bought the rig? Its not the consumers fault (to a degree). They are relying on a quality product by the manufactuer. If the manufacturer put the part on, it MUST be the right size. Right? WRONG! There are NO regulations folks. Get yourself educated BEFORE you buy a rig. And always assume that there is no engineering or real quality control. We got rid of the G tires and put H tires on. They are from China and have already been about 10,000 miles with zero issues. Do you check your tire pressure every time you depart?

I’m in an RV Park in Indiana right now. You should see all of the junk surrounding us! This park has a repair service here. They are booked up and getting rich every day!

RV junk aside, we still love the RV life, and what it represents. We’ve met a lot of great people and seen a lot of fabulous sites. I just wish someone would start a quality RV company. I would be the first in line! But we won’t make the same mistake twice. Once this rig is gone, we’re out of the RV life!

Ken (@guest_56204)
4 years ago
Reply to  TravelingMan

TM, as far as your roof goes you should take a strong look at RV Armor or Flex Armor RV roofing. Both are good companies and offer lifetime warranties at approximately half of what you are looking at with a new rubber roof. Your roof will also be better sealed around the perimeter and at all holes on it (vents, AC, screw holes). I had this done 4 years ago and have yet to need to add lap sealant.

TravelingMan (@guest_56472)
4 years ago
Reply to  Ken

I appreciate the feedback.

Greetings Ken,

I looked at both of the products you mentioned. Both have their merits. I have been to watch the installation techniques of both and had originally and strongly considered both.

The reason I am choosing this alternative route is the specific product and techniques. It’s not the cheap RV manufacturer product. It is a commercial roof installed using commercial methods.

One of the unique aspects of this particular company is that they are GAF certified which means GAF stands behind these trained technicians. They also watch over them. After all roofing equipment has been removed, they construct “curbs” and install flash guards. They also heat seal all roofing products. The TPO type materials are also thicker and far more resistant to tears from branches or anything else.

We plan to travel for many years (at least as long as the RV holds out anyway). I am taking this one time hit to make sure that the roof is sealed as best as it can be. I am really impressed with the process of this company. Water intrusion is one of the most damaging things that can be done to an RV.

Before making all of these repairs (including the roof), we thought about buying a newer RV. But then came to the conclusion that all RVs are junk and we would just have to do this all over again if we traded rigs. So, we are making this one the best that it CAN be.

Once again, I really appreciate your feedback. I don’t know everything and look at all suggestions with an open mind. In this particular case, I have done a lot of research. I also have a maintenance, construction and engineering background so there is not a lot these cheap manufacturers can do that I can’t do better (especially with your kind of help).

Many thanks again.

Scooter (@guest_55835)
4 years ago

Been running st tires on all our trailers with no issues but I am A retentive about checking my tires. We did upgrade to the GY Endurance on both our 5er and boat. Bumped up both to the next higher load range. Our first TT wore load range Cs which after putting a pencil to it were at 100% load with the trailer at MTGW and most aft cg (10% tongue weight). Immediately bought the next highest load range for that trailer.

peterb (@guest_55826)
4 years ago

Been using LT tires for many, many years, always been happy with them. As soon as the stock tire ST comes apart I switch all to LT. Had problems with all most every ST tire I’ve had, on several different RV’s

Roger Marble (@guest_56414)
4 years ago
Reply to  peterb

When you make the switch be sure to get an LT that is rated for at least 115% of your actual scale weight on the heavy end of your axle. AND inflate all tires on the trailer to that pressure.

Jeff Reck (@guest_55767)
4 years ago

When I bought my travel trailer earlier this year, I told the dealer I wanted to pay extra to have the china bomb tires replaced with better ones. To your point, the dealer said he had never been asked to do that by a customer before. He was pretty surprised but happily complied to make the sale.

Steven Scheinin (@guest_55745)
4 years ago

I have ST tires on my 5th wheel. I notice that when I am parking in a tight campsite those tires have a lot of “flex”, so much so I was alarmed the first time I saw that. It is now time to purchase new tires, and I am staying with ST for that reason. I don’t think LT tires are made for 5th wheels, or have the ability to “flex” at the same degree as ST’s.

Roger Marble (@guest_56142)
4 years ago

In my opinion, I would think an LT tire with equal or greater load capacity than an ST tire would probably deliver longer life. This is because the Formula used for ST tires somehow predicts an increased load capacity of 10 to 20% greater than an equal sized LT tire for the same inflation. You can confirm this by reviewing the Load & inflation tables yourself. SImply select a size (the numbers that give you the width, rim and aspect ratio) and compare the load capacity as a specific inflation for ST vs LT. I believe you will see ST claim is always higher. Then ask yourself…If a tire company has the materials to make a tire with greater load capacity in an ST type why aren’t they using the same materials in their LT tires?

Sign up for the

RVtravel Newsletter

Sign up and receive 3 FREE RV Checklists: Set-Up, Take-Down and Packing List.