with RV tire expert Roger Marble
Is it true a pickup tire is better than a trailer tire? That’s a question I received the other day. Here is my reply.
Well, I’m not sure. Is spaghetti better than lasagna?
OK, seriously. There’s no good way to answer the question as an LT tire is intended for passenger-carrying vehicles while ST-type tires are specifically designed for trailers not carrying any passengers.
The load formula for these two different type tires is different, just as the formula for P-type or passenger-car-type tires are different. ST-type tires are rated for about 15% greater load capacity, depending on the specific size, but with a max speed of 65 mph. So if you never exceed 65 mph, ST type is “better” as they are rated for higher load.
BUT DOT testing for LT-type tires is more substantial (more difficult) and has more requirements than the requirements for ST-type tires. So if you believe that being able to pass more difficult tests indicates a “better” tire and you want better durability, then LT tires are better.
Now if you want to compare two different size or different load range tires but with the same load capacity, then IMO most LT tires are probably better than most ST-type tires based on their ability to pass the more difficult DOT tests which are based on load.
BUT what if you consider lower cost your “measure” when comparing tires? You might find that many ST-type tires have a lower price than many LT-type tires.
Read more from Roger Marble on his blog at RVtiresafety.net.
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For safety purposes you should be using an ST rated tire on your towed trailer. Tires rated for your truck (LT) are made with a softer sidewall and being more pliable have more side flex which can cause the tires on your trailer to swim through corners causing more potential for tipping. My recommend always to lean toward safety. Also one or two steps above manufactures tag ratings.
I tried a set of 16″ trailer tires on my 1 ton truck & IMHO they worked better, tracked better than any truck tire I’ve tried. Just my experience YMMV.
If by “trailer tire” you mean “ST” type tire, that is definitely not a good thing to do as ST tires are not approved by DOT for use on vehicles that carry passengers. I would recommend you get them off ASAP.
I have always used lT truck tires and had real good luck but most trailer tires are 16″ and truck tries are 17 ” so I started using 16″ truck tires but they get hotter than trailer tires and blow out so I’m useing trailer tires, but I’m useing 12 ply instead of 10 ply. I drive a pickup and 14000 gvw trailer every day with equipment on it and haven’t had any problem at all
Well Mike you have a number of things going on that might confuse some folks. LT tires are definitely available in 16″ wheel sizes. Most Class-C RV motorhomes come with 16″ tires. I wonder about the tire temperature statement. Did you just swap from ST to LT but used the same “size” tire? You do need to remember that an LT tire has a lower load capacity than an ST tire of the same physical size. I have written a number of times in my RVTireSafety.Net blog about “Blowouts” and how many people confuse a tire failing in the sidewall because of an air leak as a basic failure of the tire structure. Any tire can be made to fail if it doesn’t have the required inflation pressure.
My SunnyBrook called for LT tires. I tried ST because “they are meant for trailers.” Nothing but blowouts. Moved up two load ranges from an E to G and put on G614s. NO MORE blowouts. And I keep my speed to 65MPH.
I am pretty disappointed (and confused) with your answer. I was told that ST tires are especially made for trailers because of the pressure trailer tires put on the sidewall (as you turn or back up). LT tires are made for straight, stay in your lane, type of driving. You seem to be saying both tires are okay for an RV, it just depends on your budget which tire is “more” okay. Am I correct in this analysis?
Yes comparing the two types of tires can be confusing. You need to look at the stated load capacity and the recommended normal operating speed. ST tires have a higher claimed load capacity because they have a lower speed capability. That is the primary trade-off. I don’t see any significant difference in the sidewall of ST vs LT tires and many of the so-called Blowouts on ST tires is the result of overload, over-speed and low inflation. IMO ST tires were “invented” to allow a lower cost tire to be used by RV companies on trailers back in the 70’s when the highway speed limit was 55 mph. Check out my blog RVTireSafety.net for a lot more in depth articles on ST vs LT tires
A great question and good answer too. I have wondered about this very question intending to upgrade tires when the time comes. I am very grateful for you being on this forum and always look forward to reading you piece on tires.
Roger, the reader asked a general Y/N question but your answer was anything but. LOL I deduced from your answer that due to the more stringent testing that it should be a Yes. I had a blowout on my junk OEM ST tire with less that 3K on them. I pull at conservative speeds usually never over 65 typically 2 or 3 MPH less than the speed limit and in the right lane but that did not prevent my tire from failing. MY remedy was to purchase a set of GY G614’s (my G614’s are LT tires but now they are branded as ST tires) and I’ve not had another issue.
James, Yes people want simple Yes no answer to “What is the best tire” when the reality of life is that there are just too many variables (load and weight of RV, how much you are willing to pay, do you have enough space for a different tire etc) You seem to feel your G614’s are a better tire. OK did they cost the same as the OE ST tires? Same inflation? Same physical size? SO you see how it is impossible to simply say that G614’s are the best tire, without recognizing the other features that are different.