It's time to shop for new trailer tires. I've noticed a fair number of people running LT rated tires on their trailers. Since I can pick up a set of LT 235/85-16 tires for a lot less than the equivalent name brand trailer tire I'm curious if there's a down side. Are they legal to use on a trailer? I know standard P rated tires are a bad idea due to sidewall flex and their weight rating. Anyone have any experience?
Most LT tires are now rated for trailer use by the manufacturer. Out of stubbornness or habit I haven't been able to convince myself to try running them but if they're trailer rated and the weight rating is appropriate then there should be no downside to running them.
We run LT tires on all the trailer with no ill effects so far.
I have done it with lackluster results.
Trailer tires and vehicle tires are completely different animals. Vehicle tires are designed for all kinds of operation; cornering, accepting torque, quiet smooth ride, treadwear, traction, etc. Trailer tires are designed to take lots of weight, but they don't have to take torque (except modest braking if you have trailer brakes) or worry about noise. They are a purpose-built tire for one purpose and they excel at what they do because of it.
LT tires are rated for a certain weight knowing that the vehicle will only see that weight on very rare occasions, so they are designed for intermittent high loads. Since most people don't use a trailer unless they're actually using it to haul something, trailer tires are designed to take that weight for nearly 100% of duty cycle. If you take an LT tire rated for 2500 lbs, and an ST tire rated for 2500 lbs, inflate them both to max and then put 2500 lbs on them, the LT tire will deform far more than the trailer tire. Deformation means heat, heat means death. In short, weight ratings on the two different designs are apples and oranges. I have four E-range ST trailer tires on my 32' travel trailer with a GVW of 9800 lbs. My spare is an E-range LT. The one time I used the spare, it was very squishy compared to the STs and got much warmer. It made it 300 miles, but it showed significant sidewall heat damage so I threw it away and got an ST to replace it.
The other thing about ST tires is the sidewall rubber compound. They tend to be much higher resistance to UV since most trailer tires will expire from age before treadwear.
If you're just hauling a Miata, either one is fine. If you have a travel trailer filled with canned food, a full water tank, and 6 cases of beer, stick with ST tires. I just never understood such a strong desire some people have to use a tire that wasn't designed for trailer use on their trailers, especially when trailer tires don't really cost any more than an LT tire... and in many cases they're cheaper.
The question is though... how do you find a good trailer tire? They're all made in China and Korea now... which doesn't have to be a bad thing, but it seems that it is a bad thing. Growing up in Carlisle, PA we had the Carlisle tire factory and they made great stuff. They moved all production to china and I have had such awful experience with them that I gave up. They can't even make a decent golf cart tire now.
In reply to Curtis :
Your last point is really the issue. I have a set of factory installed no name 235/80-16 tires on our 3 horse gooseneck trailer. This is a relatively new trailer with limited mileage and the tires are shot. All of the recent reviews of ST tires seem to indicate quality concerns even with the name brand tires.
I'm looking at a set of LT 245/75-16s as a replacement. The load rating of the existing tires is 2204lbs per tire, not sure how the manufacturer gets away with this as the trailer is rated at 10,000lbs. The replacement LT tires are rated a over 3000lbs each.
Yup... they're rated at 3000 lbs but the factory gives them about a 20% duty cycle at that weight. ST tires rated at 2500lbs would be better since they're rated for more like 90% duty cycle at that weight.
My F150-7700 has a GVW of 7700, but it has the same springs, trans, tires, axles, brakes, and coolers as an F250 rated for 8600. So, in theory, my F150 at 7700 GVW would last longer than an F250 at its 8600 GVW. They're just numbers that project a safe outlook without causing lawsuits and warranty claims. Its no different than buying a ladder. An aluminum cheapy step ladder might be rated for 225 lbs because they know it will get used once a year by a homeowner painting a wall. A good, commercial fiberglass ladder might be rated for 250 lbs even though it could probably take much more because they know it will get used all day, every day by a pro painter.
They don't publish those duty cycle numbers for tires. They test tires at weights and come up with a max weight based on how they hold up. In the case of an LT tire, they know that they won't spend as much time being used at that weight, so they can fluff the number a bit.
It gets even murkier with P-metric tires. They know that they will spend even less time than a truck at max weight.
I totally understand the trouble finding a good ST tire. I personally wouldn't use LT tires to haul horses unless you're headed to the glue factory. I would continue to research. I have had the best luck with Gladiator and Load Star. The Goodyears I had weren't any better but they cost more. I just sold a 26' cargo trailer and I had put LoadStar E-range on it. I think they were 235/80-16, 90 psi max, 3500lb each. I overloaded the crap out of the 10k gvw trailer on a trip from TX to PA and they took every bit of it and didn't whine. No tread cupping, no heat, no deforming, no squishy. The torsion axles, on the other hand, didn't like it too much. They were under $100 each.
The real bottom line is how the LT tires take the weight. E-range LT tires have pretty stiff sidewalls... not as a means of holding weight, but as a means of containing 80 psi to suspend the weight. There really isn't an issue with using LT tires as long as they don't deform. If you can't get enough pressure to prevent squishy sidewalls, then it doesn't matter what the max weight is on the sidewall. I would just hate for you to load up three precious Walker mares and end up blowing a tire.
Another quick example: The previous owner of my F150-7700 was cheap and got 245/75-16 in P-metric. On paper, they seem OK. They are rated for 2250 lbs at 44 max psi. That suggests they would support a vehicle with a GVW of 9000 lbs. That is complete bullE36 M3. At 44 psi, they have a noticeable bulge when the truck is completely empty. They would be great on a Jeep or a Tacoma, not a full size truck.
If you put those on your gooseneck and inflate them to 44 psi and then load the trailer to 9000 lbs, you wouldn't make it 200 miles.
Now... if you had LT E-range tires rated for 2250 each, they would do worlds better.
ST tires rated for 2250 each would be light years ahead of both.
Tire weight ratings are apples and tomatoes when comparing between types.
I ran LT tires on my enclosed trailer. They got the job done.
I run ST tires on my open deck. They also get the job done.
The ST tires are a little stiffer so the trailer bangs a little more. The LT tires ran cooler and smoother.
If the trailer spends a lot of time sitting, I'd probably go with the ST tires. They withstand sun damage better than the LT tires did. If it spends most of it's life on the road, go with the LTs. They will have better tread wear.
All Goodyear Endurance trailer tires are made in the USA.
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