Originally Posted by HSVBamaBob
The LT vs ST debate is almost like the 1/2 towing light weight 5er debate.
No clear consensus and a LOT of personal opinions
I believe I saw a post from WMTire (Site team and tire professional that outlined the whys and why nots of LT & ST tires)
But I remember a quote from a tire seminar I went to last year: "Special trailer tires are designed with a thicker side wall than passenger vehicle tires because they need to handle more vertical load."
Also, I have a pretty good RV101 Article. here is the link:
Trailer Towing – ST Tires vs. LT Tires | RV 101® your education source for RV information
I wasn't that impressed with the article. The part about don't expect the same life expectancy from ST tires. Why not? If an ST tire is designed to carry a certain load and handle the unique aspects of trailering, then it should have a tire life equal to an LT tire used on a truck. When I first started RVing, I recall the guideline for ST tires was 7 yrs. I owned my 1st fiver for 7 yrs and sold it with the original ST tires. Today, all the ST manufacturers say replacement may be necessary after just 3 yrs. What has changed?
Then the part about tires degrading from the inside out and the affects of over/under inflation. Why would that apply only to ST tires? Prior to factory TPMS, most of us probably had the wrong inflation for our LT tires as well. And as far as abuse, my truck and fiver both pretty much hit the same quantity of potholes and curbs while towing but the truck running solo also hits many more. The only time the fiver tires see more stress is with sharp jack-knifing manuvers, which I rarely do.
Finally, the topic of load capacity, neither a 3400 lb capacity ST tire or a 3042 lb capacity LT tire will work on a 7K axle, yet both will work on a 6K axle and there are no other axle capacities in between, so switching to an LT tire may not mean giving up any usable capacity. I switched from factory supplied 3400 lb capacity ST tires a few yrs ago to 3042 lb LTs, BFG Commercial T/A's. Both are overkill since my axles are just rated for 5200 lbs. Prior to my decision, at a multi brand rally, I checked the factory stickers for all the TTs and fivers. Roughly 1/3 did not specify ST or LT, 1/3 did specify ST and 1/3 specified LT. Most of the units that specified LT tires were the heavier brands like DRV.
So, if ST tires are so specially engineered for trailer use, how can rv manufacturers with expensive, heavy units "get by" without them? And if switching from ST to LT tires is such a risky thing, where are all the disaster stories from those owners on the forums?