People are always in search of "performance improvements." Whether it’s six-pack abs or more hair, we ponder new and better options ®“ and sometimes additives ®“ to enhance one thing or another.
It’s really no different with commercial truck tires. Over the last few years, there has been a growing market for a variety of materials, designed to be placed inside truck tire casings, to enhance on-road performance.
As with most technical components, though, a little knowledge (or misinformation) can be dangerous. The best opportunity for improvement, or, in the worst case, protection from an expensive mistake, is to obtain accurate information about exactly what any specific new product can and cannot deliver for your dealership and for your commercial customers.
There are generally three different groups of tire additives, each with valid applications. Some are designed for specific types of tires and/or vocational service conditions.
First are the sealants, designed to minimize air loss from punctures of the innerliner. These are most often used in mixed service or off-road applications where tires are subjected to penetrations, cuts or other hazards that can cause inflation loss ®“ especially in conditions that make immediate repair difficult or impossible. Underground mining, local waste hauling, and scrap yard service are typical of these applications.
Some sealants are liquid-based, freely moving inside the tire "seeking" punctures to plug. Others are semi-solid so that they conform to seal punctures, for example, but do not change position significantly inside the tire.
A second group of additives is sometimes promoted as "tire coolant." The theory here seems to be that, by reducing tire running temperatures, these additives can increase durability, treadwear, and generally allow the tire to "age" more gracefully.
Many tire engineers question these claims, saying that modern radial highway tires already run at temperatures considerably lower than their predecessors, and that further reductions are likely to be of little value in regular use. However, some possible exceptions may be conditions of extreme overload or excessive brake heat generation, such as in off-road earthmoving hauls.
A third category of additive claims to improve vehicle ride. Usually recommended as a substitute for traditional lead weights tire tire/wheel balance correction, these materials come in liquid, solid and powder forms. All have claimed to improve truck ride. Despite initial concerns from tire engineers, some have been used very successfully for years. Others were introduced and quickly left the marketplace.
Of all the tire additives we’ve discussed here, those targeting ride improvement are probably the most interesting. Some of these products are well accepted, especially among large coach RV owners, who prefer the additives to traditional balance correction as a means of gaining a vibration-free ride.
There are also several trends and market factors impacting high-speed over-the-road truck operations that tend to favor this category of additives.
First, most axle-end components, including tires, wheels, hubs and drums (or rotors) have improved in uniformity, making them less prone to vibration from pure out-of-balance or high runout conditions. Some component manufacturers even claim that, by using their branded products, tire/wheel assemblies may not require traditional mechanical balance correction.
Secondly, highway truck suspensions have become more compliant (softer riding) and, therefore, more responsive to damping (vs. balance correction) as a method of controlling ride disturbances caused by road irregularities and other sources of shock input.
Another factor is the emphasis that trucking companies place on cab ride-comfort as a means of attracting and retaining quality drivers. And reducing vibration also reduces driver fatigue, which, in turn, improves driver safety.
Finally, there are regulatory moves afoot to ban the use of lead (including wheel weights) on new vehicles. While nothing firm has started in North America, many European markets have already begun switching over to tin and other materials as substitutes for lead in weights. It may not be that long before we see similar moves made on this side of the pond.
Get Answers First
While the validity of performance claims for different types of tire additives is beyond the scope of this limited space, there are certain things you and your customers should know about any new product before trying it inside tubeless radial truck tires.
There are numerous questions that your tire sales professionals should be prepared to address, for example:
®′ Is the material chemically compatible with the tire and the wheel paint or coating it will contact in normal use over expected time and temperature exposures?
®′ Is the material non-abrasive to the interior surfaces/finishes of the tire/wheel?
®′ Will the material inhibit casing inspection prior to repairing, retreading or other service procedures? Is any costly, time-consuming clean-up required to assure high quality interior casing inspection?
®′ How long has the product been used in the industry, and can user references be furnished?
®′ Will the product have any effect on tire or wheel warranties?
®′ Will the material cause any loss in inflation retention integrity?
®′ Are any related inflation/valve system components required or provided?
®′ What are the recommended product removal procedures when the tire is dismounted?
®′ Are there any disposal or toxic material issues?
Perhaps most importantly, what are the specific performance claims? For example, it is unlikely that any single product will be effective as a sealant and coolant and for ride improvement. Can the manufacturer or distributor provide credible, independent test data in support of the claimed performance benefits?
Many industry observers believe that certain of the products discussed above have bright futures in over-the-road truck applications. But, remember, most of the world’s magic is restricted to the entertainment industry, not the transportation business. Obtaining reliable information from the right sources is the best place to start.