Tires: life span, vs LT/P, storage, tips and inflation

[lucynricky]

Haven’t posted the following in a long time. It’s time.

Some basic tips from literature and conversations with carlisle, goodyear, michelin, discounttires, etc., on trailer tires.

“It’s the air inside the tire, not the tire, that supports the RV.”

Once I heeded the following, I was getting 15,000 to 17,000 miles on both C and D load range tires on three different rigs - 5er/truck, Jeep CG/tiny trailer, Jeep CG/med trailer including one stunning year of 19,797 miles.

LIFE SPAN
• Three to five years is the projected life of a normal trailer tire (whether used or not).
• The life of a trailer tire is limited by time and duty cycles.
• Depending upon the trailer duty cycle (storage time vs. actual time in use under load) the mileage expectation of radial trailer tire can be from 5,000 to 12,000 miles.

DIFFERENCES FROM TRUCK/PASSENGER TIRES
– Polyester cords in an ST tire are bigger than in a comparable P or LT tire.
– Steel cords used in ST tires have a larger diameter and greater tensile strength to meet additional load requirements.
– ST tire rubber compounds contain chemicals to resist weather and ozone cracking, particularly conditions resulting from extended storage and the unusual duty cycles of trailer tires.
– The slightly shallower tread depth of a trailer tire reduces sway and rides cooler, which adds to tire longevity.
– ST tires feature stiffer sidewalls, especially in the lower section which:
– Reduces sidewall flexing causing the trailer to track straighter.
– Diminishes the risk of trailer sway.
– Lessens the risk of sidewall puncture and blowout.
– ST tires generally offer approximately 10% percent more load
capacity than a similar LT tire and nearly 40% more than a P passenger tire.

STORAGE ON THE VEHICLE - APPLIES TO TRUCK AND PASSENGER TIRES ALSO.
• Thoroughly clean (wash don’t scrub) before storing and occasionally after.
• Avoid ozone (generators, etc.) and asphalt (all petroleum products).
• Well drained flat surface: gravel, concrete, etc. (contrary to web, concrete will NOT hurt). Use a piece of cardboard if in doubt about surface.
• Run for 25 miles or more every three months, or will get flat spots; also activates additives that protect the tires. (Michelin recommends running LT tires every 30 days!)
• Increase inflation 25 percent (do not exceed rim limits). Check monthly.

GENERAL TIPS AND INFO
• Keep tires clean, "Each Goodyear RV tire contains additives, and as the tire rolls, they rise to the surface of the rubber to help protect the tires from cracking. Goodyear RV tires do not need any other dressings, appearance products or covers to help protect them. In fact, using products that contain alcohol, petroleum or silicone products may cause your Goodyear RV tires to deteriorate, crack and age more quickly."
• Keep correct inflation - over (not over max) is better than under.
• Do not drive over 65 (or inflate at plus 10 psi).
• Check tire pressure when coldest time of day (or they could become under inflated).
• Tires are made to handle over inflation, not under inflation.
• For every 10° F increase in temperature, tire pressures will increase about 2%.
• For every 1000 foot increase in elevation, tire pressure increases about 0.5 pounds.
• Overinflation will NOT increase load carrying capacity.
• 33% of RV’s had overloaded tires. From Recreational Vehicle Safety Education Foundation (RVSEF) who weighed over 27,000 motor homes and trailers. Most of the weight was on the rear.Twenty-two percent of all rear tires were overloaded. And weight distribution was so poor that about 28 percent of all motor homes were out of balance by 400 pounds or more from one axle end to the other.

UNDERINFLATION
• For every 5 psi underinflated, lose about 5% of load rating; varies slightly by tire type, size, and range.
• Bridgestone/Firestone survey: 4 our of 5 RV's have at least one underinflated tire, a third of which were dangerously underinflated and at risk for failure.
• Underinflation is the number one cause of trailer tire failure. Low inflation pressure creates abnormal tire flexing and excessive heat. A tire can lose up to half of its air pressure and not appear to be flat. Check inflation with a quality tire gauge. Operation of a trailer tire that is 30 percent under-inflated can reduce tire lifespan by approximately 55%. Underinflation causes: – Tire damage and failure. – Ride and handling disturbance. – Reduction of tire life. – Decreased fuel efficiency by as much as 10 percent.

Thanks for reading - Happy Trails