Facts about Trailer Tires
Trailer Tire Applications
Trailer tires are designed for use on trailer axles only. They are not built to handle the loads applied to, or the traction requirements of, any 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.
Never mount "ST" or "LT" trailer tires on any passenger car or light truck.
Why Use an "ST" Tire
"ST" tires feature materials and construction needs 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 also contain more chemicals to resist weather and ozone cracking.
Inflation
Always inflate trailer tires to the maximum inflation indicated on the sidewalls.
Check inflation when the tires are cool and have not yet been exposed to sunlight.
If the tires are hot to the touch from operation, add three psi to the max inflation.
Note: Under inflation 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 consider replacing 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 will eventually weaken trailer tires.
In approximately three years, roughly one-third of the tire's strength is gone.
Three to five years is considered the normal projected life of a trailer tire.
It is suggested that trailer tires should be replaced after three to four years of service regardless of tread depth or tire appearance.
Mileage
Trailer tires were or are not designed to be worn out.
The life of a trailer tire is limited by time and duty cycles.
The mileage expectation of a trailer tire is only 5,000 to 12,000 miles.
Storage
The ideal storage for trailer tires is in a cool, dark garage at maximum inflation.
Consider using 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 appear like they're worn out or not.
Trailer Tire Warranty
The OE (original equipment) warranty goes into effect when the trailer / tires are purchased.
So you’re in the market of buying a trailer. Often, people think the tires are new because they appear new. As everyone who’s owned a trailer knows, most trailer tires simply don't last very long. It's actually easy to tell the age of a tire. It's posted right on the tire. Anytime you buying tires, you should check their age.
Forget all the numbers and letters except for the 5107. The other numbers or letters refer to the plant where the tires were manufactured. Who cares? The 5107 is what is important. The 51 stands for the fifty first week of the year the in 07. So this tire was manufactured the third week of December 2007. If the number was 1310 the tire would have been manufactured approximately April 2010.
Maybe you’ll sometime find this useful in the future.
Posted by blog.houseboatodyssey1.com at 9/28/2010 8:31 AM 
Categories: Trailering, Boating, Various 101's, Maintenace
Tags: LT Facts Tire Capacity ST Tires Storage Trailer 101 Boat
Categories: Trailering, Boating, Various 101's, Maintenace
Tags: LT Facts Tire Capacity ST Tires Storage Trailer 101 Boat
There really is a lot to think about in relation to trailer tires. I never used to consider all of these factors. It seems like a simple thing, the lowly little tire, yet they are anything but a minor consideration. In a way they are everything, as they are the major components that bears the weight of the load. I like your thoroughness in the above post, and how you detail all of these important considerations. Thanks!
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Our pontoon houseboat is on the heavy side and it most certainly would not be fun to fix a flat or worse yet have a blowout.We carefully check the air pressure and visually check for signs of wear etc. So far we have not had any problems, thank goodness. Thank you for the nice comment.
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Write more often
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