Towing Things to know about trailer tires

[SaskCampers]

So you want some trailer tire facts?

Well then.. Here You go.


Trailer Tire Applications

• Trailer tires are designed for use on trailer axle positions only. They are not built to handle the loads applied to, or the traction required by, drive or steering axles.
• An "LT" designation on a trailer tire size specifies load range only. It is not designed for use on light trucks.
• Do not mount "ST" or "LT" trailer tires on passenger cars or light trucks.

Inflation

• Always inflate trailer tires to the maximum inflation indicated on the sidewall.
• Check inflation when the tires are cool and have not been exposed to the sun.
• If the tires are hot to the touch from operation, add three psi to the max inflation.
• Underinflation is the number one cause of trailer tire failure.

Load Carrying Capacity

• All tires must be identical in size for the tires to properly manage the weight of the trailer.
• The combined capacity of the tires must equal or exceed the Gross Vehicle Weight (GVW) of the axle.
• The combined capacity of all of the tires should exceed the loaded trailer weight by 20 percent.
• If the actual weight is not available, use the trailer GVW. If a tire fails on a tandem axle trailer, you should replace both tires on that side. The remaining tire is likely to have been subjected to excessive loading.
• If the tires are replaced with tires of larger diameter, the tongue height may need to be adjusted to maintain proper weight distribution.

Speed

• All "ST" tires have a maximum speed rating of 65 mph.
• As heat builds up, the tire's structure starts to disintegrate and weaken.
• The load carrying capacity gradually decreases as the heat and stresses generated by higher speed increases.

Time

• Time and the elements weaken a trailer tire.
• In approximately three years, roughly one-third of the tire's strength is gone.
• Three to five years is the projected life of a normal trailer tire.
• It is suggested that trailer tires be replaced after three to four years of service regardless of tread depth or tire appearance.

Mileage

• Trailer tires are not designed to wear out.
• The life of a trailer tire is limited by time and duty cycles.
• The mileage expectation of a trailer tire is 5,000 to 12,000 miles.

Why Use An "ST" Tire

• "ST" tires feature materials and construction to meet the higher load requirements and demands of trailering.
• The polyester cords are bigger than they would be for a comparable "P" or "LT" tire.
• The steel cords have a larger diameter and greater tensile strength to meet the additional load requirements.
• "ST" tire rubber compounds contain more chemicals to resist weather and ozone cracking.

Storage

• The ideal storage for trailer tires is in a cool, dark garage at maximum inflation.
• Use tire covers to protect the tires from direct sunlight.
• Use thin plywood sections between the tire and the pavement.
• For long term storage, put the trailer on blocks to take the weight off the tires. Then lower the air pressure and cover the tires to protect them from direct sunlight.

Maintenance

• Clean the tires using mild soap and water.
• Do not use tire-care products containing alcohol or petroleum distillates.
• Inspect the tires for any cuts, snags, bulges or punctures.
• Check the inflation before towing and again before the return trip.

Keys to Avoiding Trouble

• Make sure your rig is equipped with the proper tires.
• Maintain the tires meticulously.
• Replace trailer tires every three to five years, whether they look like they're worn out or not.

These facts are courtesy of Discount Tire.

[jledwards0117]

OK, I'll bite. Lists like this are made for "discussion".

Most of this makes pretty good sense and I hesitate to question the wisdom of the Discount Tire folks. However, I have to ask: If you should always keep your tires at the maximum inflation, why do tire manufacturers put out all these inflation tables -- just to confuse us? Do they want us to under-inflate so that we'll ruin the tires and buy another set?

Here's another: One trip from Houston to the northwest and back can put 5K-6K miles on my fiver. If the life expectancy of trailer tires is 5K-12K miles, then I need to buy a new set of tires after each of these long trips I take?

Inquiring minds ...

Jim

[rockwood06]

In most cases tires on campers and trailers are changed because of age not milage, these unit set most of the time and dry rot before they wear out.
Check the date codes on the tires as well, the tires on my camper were two years old and i bought my camper new in 2006, the date code was 04.

But with new cars and trucks, i have found that the tires that are installed as they come off of the assembly line are dated as the same year the vehicles are produced.

[Herk7769]

Originally Posted by jledwards0117

If you should always keep your tires at the maximum inflation, why do tire manufacturers put out all these inflation tables -- just to confuse us? Do they want us to under-inflate so that we'll ruin the tires and buy another set?

If the life expectancy of trailer tires is 5K-12K miles, then I need to buy a new set of tires after each of these long trips I take?

Jim, John was posting a direct quote from the Discount Tire folks. While they are a source of excellent information, some "generalizations" slipped into their list. You picked two of the most glaring.

Generally:

Since trailer manufacturers put the cheapest and lowest rated ST tires they can buy, that are certified for the MAX GVWR of the camper, they will only carry the GVWR at max cold inflation pressure (CIP). Additionally, if you do use LESS than max CIP, YOU MUST WEIGHT THE CAMPER EVERY TIME. While I am sort of a weight Nazi, even I don't weigh every trip even though the load carried changes slightly every time we go out, depending on season and location. I also have D rated tires on my camper and it came with C rated tires that were maxed out at 50 PSI CIP to carry the GVWR. The MAX CIP on a D rated tire is 65 PSI CIP. If I ran the D rated tire at 65 PSI CIP, the camper's tires would wear on the center rib and not evenly across the tread face. Also, at 65 PSI the trailer would bounce down the highway with tires that hard. I weighed the camper with my normal stuff loaded for camping and run 55 PSI CIP. This gives me what I need and a nice smooth ride down the highway.

As to the mileage, ST tires are not designed with mileage in mind as a design feature. That is NOT to say you won't get better mileage. Since most tires rot off trailers, not wear off, folks that are on the road A LOT, get better mileage than those who are not. You and I are definitely "atypical" campers by that definition and not the type the Discount tire post was aimed at.

[KyDan]

" The mileage expectation of a trailer tire is 5,000 to 12,000 miles."

WTF???

These guys are just trying to sell tires!

[flyrotor]

Originally Posted by KyDan

" The mileage expectation of a trailer tire is 5,000 to 12,000 miles."

WTF???

These guys are just trying to sell tires!

No, that's taking into consideration the average seasonal camper who goes a few times a year.

Do the math - 500 to 2000 miles a year,
Life span - every 5-6 years you should replace your tires
which equals 3,000 to 12,000 miles.

[KyDan]

They're trying to sell tires!

Granted old tires should be replaced but they could
say "tires should be replaced every 5 years" instead
they say 5k to 12k miles.
I put over 5000 on mine just last summer!
They still look new as far as tread wear and I don't see
any tiny cracks in the side walls or between tread lines
so I'm going another year at least.

[zx5chris]

okay anyone have an odometer on their trailer? Use time as a guide. Who wants to be stuck on the side of the road changing a tire, anytime? The automotive industry has changed the term 'recommended service' to 'scheduled maintenance' for a reason - overall ownership satisfaction.

[jledwards0117]

Lou (herk7769),
Thanks for the detailed reply. It seemed to me that the statements must be generalizations, but DT should really consider qualifying statements like that so that they don't mislead people looking for information on how to run their tires. Also, from what I've seen, there seem to be a lot more LT tires on trailers rather than ST.

I just replaced the tires on my Sierra 345RET after 2 blowouts, about 60 miles apart, of the Trail Express tires that came from the factory. And, yes, they had only 6k or so miles on them.

It really upset me, as I had just checked them before starting the trip. They looked fine and were properly inflated. Weight was not a factor -- I'm running about 2k less than the tire ratings. Besides the trip delay, hassle of changing tires on the road, and expense of new tires, I now have to deal with the damage to the trailer that the blowouts caused. Hopefully, I'm good to go now. Replaced all the OEM tires (Load Rating "E") with new Goodyear tires (G614 RST, LR "G"). That's probably overkill, for the situation, but gives me some peace of mind.

Sorry, just venting. Don't want to subvert the thread, so I'd ask everyone to please not reply about crappy Chinese tires and the like. I really appreciate the opportunity the forum offers for shared information and for all of you with great experience who are willing to share with the rest of us.

Thanks again.
Jim

[johnsmith12]

Originally Posted by KyDan

" The mileage expectation of a trailer tire is 5,000 to 12,000 miles."

WTF???

These guys are just trying to sell tires!

I used to sell tires and most of my customers never came close to getting 12,000 miles on their trailer tires. Most people don't check the air pressure before taking off! I'd have customers that would overload their trailer, never check the air pressure and then be furious when their trailer tires would blow! It was always the tires fault and we covered many tires under warranty that would shouldn't have. I agree with many posts on here, trailer tires should last longer than 5k-12k miles IF they are taken care of through proper air inflation, not overloading the trailer beyond the weight capacity of the tires, and also covering the tires when possible from excess sun exposure.