RV Tire Safety: More on Goodyear ST- versus LT-type tires

6

with RV tire expert Roger Marble

Had a couple of comments on my recent post on LT versus ST type tires for RV trailers.

Alain said:
Now, I am VERY confused. For years, everyone in the RV business, its commentators, its experts and other blogger forums’ so-called experts “having used this or that for soooo many years without any problems”, etc., had me believing all the hullabaloo about the ST tires’ sidewalls being much better, much stiffer and much more resistant to the particular type of flexing that occurs when driving, turning and parking travel trailers or fifth wheels than LTs. After the appearance of the ‘china-bombs syndrome’ a few years ago, people started to realize that practically all ST tires were manufactured in China anyway, whatever the ‘US brand name’ stamped on them, leaving the consumer with very few, if any, alternatives.

“Now, coincidentally, we hear that LT tires are ‘just the thing’ for trailering.

“It also appears that a handful of RV manufacturers, like Jayco, have seemingly struck a deal with Goodyear, who now has resumed manufacturing ST tires in North America, to equip their new trailers with ‘US-made ST tires’. I guess their ST tire prices have dropped again enough to catch the big manufacturer’s attention and make it worth their while.

“So I guess the real question should now be, are US-made Goodyear ST tires better, worse or equal quality to their US-made Goodyear LT tires, or why even bother to engineer ST tires at all? We shall see, in time, who wins between Beta or VHS, Plasma or LCD, Android or Apple, etc., etc., etc.”

My response:
Alain, the biggest issue is, I know of no way to do a direct comparison of ST vs. LT tires other than an expensive tire test. We can’t depend on the DOT test results. In all probability the tires all pass, simply because the RV industry and ST tire manufacturing companies were successful in getting ST tires excluded from the significant improvement in testing with updated standards in 2002. There is no question, in my mind, that the tests (FMVSS 571.119) for ST-type tires are easier to pass than the tests (FMVSS 571.139) for new Passenger and LT-type tires.

I have looked at the construction of a GY Endurance and it certainly looks better than the older Marathon design. Now remember, I do not have access to the actual specifications or material properties used by GY, but in the Endurance tire line they appear to have added a nylon cap over the steel belts. You can confirm this by reading the material list molded on a tire sidewall.

“Quality” is a tough call when you have two different specifications to start with. Isn’t quality just a measure of a tire’s ability to meet the specification for that product?

You can think of it this way. If I had two pieces of chain, one rated at 500# and another rated at 550#. They both meet a strength test of supporting the rated load and if you tested 100 pieces of each and found that all 100 passed the rates strength test, how would you rate the “quality”? You can’t say the 550# chain is better quality than the 500# chain, as they have two different goals. Just as you can’t say a 1-ton truck is better quality than a 1/2 ton truck because the 1-ton can handle more load.

Your example of Beta vs. VHS is a good example of the confusion possible. Beta was judged technically superior to VHS, but Sony made a marketing decision to prevent other companies from using the Beta specification in their video players. The result was that VHS units were less expensive so many people bought on price. Eventually, Sony lost out. Not because the “quality” of that video format wasn’t as good as VHS, but because the market was “price-sensitive” and too many people selected lower cost over better-quality product.

Gene offered:
OK, color me confused! I have always gotten the impression that ST tires and not LT tires are what I should be running on my RV. After reading this article now I’m not sure. Are you suggesting that all things being equal, LT tires of the same size, load rating, etc., are better to run on my RV? I don’t mind the cost, just want to put the best possible tire on my RV. Thanks for keeping us informed.”

To which I replied:
Gene, the problem is that “all things are not equal,” as there are no LT tires of the same size, load range, and load rating, etc., as an ST tire. There is always something that is different.

Sometimes the only option would be to go with larger size LT tires, but in some cases there is no physical room to run the available larger-size tires.

IMO, what you “should” be running are tires built to the latest industry test standards (LT) that can offer at least 15% to 25% “Reserve Load” capacity.

 

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

 ##RVT939

 

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Richard Scheich
2 months ago

It is simpler than you think to decide. If you select a LT tire that meets the weight specification for your RV you can use it, I have done it many times, it is legal (think safety) and allowed. You can not do the opposite, a ST tire can not legally be used on a passenger vehicle. The reason is safety of the ST tire, it can’t withstand side load in a steering position due to it’s sidewall construction.

Bull
3 months ago

I gave up on ST trailer tires over 15 years ago on ALL my trailers and began running LT tires. Best move I ever made concerning my trailers.

No more tread separation, blowouts or flats. I could actually replace a LT tire on my trailers because it was WORN OUT rather than a BLOWOUT!

Maybe I’m just lucky OR maybe just maybe a LT rated is a MUCH BETTER TIRE for trailer service than a trailer rated ST trailer tire. Remember the fact that for many years ALL the ST trailer tires were made off-shore and that included the absolutely horrible Goodyear Marathon tire!

Now we have the “New Goodyear Endurance” tire. Many reviews I have seen are so far so good.

Time will tell!

Dak
3 months ago

waisted time reading “this” post, don’t bother

Tom
3 months ago
Reply to  Dak

Don’t “bother” posting a reply if you don’t know the correct word to use. Wasted is the word you want.

agesilaus
3 months ago

Well I made the switch from Marathon 15 inch tires on my RV to BFG Commercial 16in LT tires on new rims. They are out next to my RV right now waiting for me to mount them. I had to go to 16 inch to get a LT tire with the right load capacity. My RV has plenty of room for the larger tires and I checked online and found it is a common modification for that unit.

I think you read the thread I started on one of the RV forums about this. You mentioned it last week.