Spring RV tire care should be a high priority

May 12, 2006|by JEFF JOHNSTON / Motor Matters

An RV's tires are among its most abused, neglected, misused and overlooked pieces of equipment. They're also probably the most important items that a driver needs to take care of on a daily basis. The combination results in a lot of unnecessary tire problems for RV users.

Tires are rightfully a frequent source of discussion among RVers, and there are some basic tire care facts that can help an RVer enjoy miles of tire-trouble-free travel. It's fairly easy to eliminate most of the causes of tire aggravation, and even danger, with a bit of attention to detail. What follows are a few frequently discussed subjects about your RV's tires. Pay heed to facts instead of campfire tales.

Common care: A simple peek at tire pressure will avoid many headaches. Make this part of your daily pre-travel routine and you'll have far fewer tire problems.

Keep the tires inflated to the maximum psi molded into the tire sidewall and you'll avoid the problems inherent to underinflation. As tire rubber flexes, it generates heat and if it's low on air it flexes and heats up more because the part hitting the pavement is squashed out and distorted. Heat is a common cause of tread or sidewall ply separation, so keep the pressure up and avoid the headaches.


Make frequent visual inspections. Check for cracks or signs of deterioration. Look at the inside sidewall as well. Spot and correct cuts, tears, bubbles or other physical defects before they become serious.

Avoid overloading: As with underinflation, overloading kills tires because it causes more carcass flex which leads to more heat. Each tire is manufactured with its maximum load rating and pressure molded into the sidewall. It might say something like "max load, 3,042 lbs at 65 psi," for example.

Most of today's trailers are pretty well matched to their tires, but it doesn't hurt to verify your trailer's weight on its axles. Add up the tire ratings for the number of tires you have and check that figure against the rig's axle weight. If the tires are overloaded, reconsider your take-along cargo or look into replacement tires of higher capacity.

Radial or bias ply: The question of using radial tires or bias-ply tires on trailers comes up frequently. Many trailers are sold new with radial tires, and radials work on trailers for the same reasons they work on cars and trucks.

However, you should never mix the two types on one rig. If the trailer has bias-ply tires and you need a replacement, you should buy a bias-ply tire. Likewise, always replace a radial with a similar tire.

Tire age: A tire's age also affects how well it's going to perform. Even if a tire has relatively few miles on it, the effects of ozone and aging can cause the tire to fail under even a moderate load.

The tire industry recommends five years as the cutoff point when you replace tires. Beyond that age, you're gambling that the rubber compounds haven't deteriorated to the point that they'll crack, cause tread separations and the like.

If you have tires that are wearing thin, use an inexpensive tread depth gauge to verify how much useable rubber you have left.

Special trailer or light truck: Some trailer tires are sold as "ST" or special trailer tires. The Goodyear Marathon is one such model. ST tires are manufactured with a rubber formula that helps resist aging better than a standard tire at some expense in tread wear. The ability to resist aging is important on a trailer tire that accumulates relatively few miles in comparison to its age.

ST tires also have stiffer sidewalls than other tire types. Look at a trailer's tires in a tight turn, especially when backing up. The sidewalls are pushed dramatically from side to side by the scrubbing action of the parallel axles moving in an arc. The ST tires with their stiffer sidewalls are said to resist possible damage due to that sidewall distortion.

A light truck or "LT" tire can also be used in place of an ST tire, as long as the tire will fit the existing wheel and wheelwell opening and it's rated to carry as much or more weight as the tire it replaces.

Keep an eye on your tires and check pressure regularly. It's one less thing you'll need to worry about as you hit the road this summer.

Copyright, Motor Matters, 2006

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