A few years ago the Technology & Maintenance Council of the American Trucking Associations (TMC) studied rogue tire tread – gators – collected from 13 stretches of highway around the U.S. The task force conducting the study found that under-inflation was the major cause of premature tire failure, sometimes compounded by undetected cuts, punctures, and other road damage.

Potentially dangerous, those big chunks of tread on the roadside have prompted more than a few civilians – and some uninformed truck drivers – to utter unkind words about “those cheap retreads”.

Retreads are getting much more than their fair share of the blame here, and they shouldn’t, but the result is the same whether it’s a new product or a retread. The fact is, if you under-inflate a tire, any tire, it will fail before its time.

Not at all incidentally, those thrown treads caused 90 fatal accidents in the U.S. last year. Something to think about.

The proportion of retreads that were judged to have failed prematurely because they were improperly retreaded – bond failure, missed nail holes, tread ‘list’ and the like – was just 8% in the latest study,” explains the TMC study’s leader and tire-management consultant Peggy Fisher. “Evidence of under-inflation, on the other hand was widespread.”

There may be other factors at play as well, such as heavier loads and higher average road speed, but in the end, it all comes back to tire pressure.

By maintaining proper tire pressure, you limit the amount of flexing that the sidewalls experience as the tire rotates. That flexing generates heat, which is often compounded by the friction-generated heat produced in the tread area. Combined, all that heat can prove fatal to tires in a short period of time. It can even cause fires.

When know the cause, and we’d all secretly admit to knowing the solution. But geez, who’s got the time to check all those tire pressures every day? It’s a load even for the one-truck owner-op, so one answer is an automatic central-tire inflation system. There are many on the market but they cost more than a grand, which may be too rich for most folks these days – even if the payback is real.

There are many variations on that theme, and simpler ones too. Like gizmos that automatically equalize pressure between duals. With just a glance, dual tire pressures can be checked and you can easily see if your tires are underinflated. The system that appears to be the most popular attaches to the dual’s hub or lug bolt and allows air transfer from one tire to the other. Its single airing point fills both tires at once, making the job quick and easy. With just a glance, you’ll instantly see changes in tire pressure because the eye of the valve contains a visual indicator to show a decrease in tire pressure.

That’s a so-called passive system, and it’s not expensive. An active system, on the other hand, will alert the driver to the problem, automatically re-inflate the tire, and record the event in its memory log. Better still, these systems can be a very real advantage in certain kinds of operations like logging and construction where lowering pressure creates better traction. They were first developed for military use.

Your Role

Owner-operator or company driver, you really can make a difference in the life expectancy of the rubber you’re riding on. Yeah, there’s a little effort required, but nothing good in life comes free.
According to the TMC, of the top five reasons for premature failure and increased operating costs, four are easily controlled at the driver level:
1) Proper monitoring and reporting of tire condition during pre-trip inspections.
2) Regular observations of actual cold tire pressure with an accurate pressure gauge.
3) Watch for rocks and nails drilling into the tires. Catch them before they puncture the casing.
4) Stay motivated. Flats mean downtime, and that costs you money.

What else can you do?
• Request an inflation pressure check prior to a regular PM inspection so the mechanics won’t forget.
• Pay special attention to trailer tires. That old TMC study revealed that 71% of the tread fragments collected had a rib pattern, indicating that they likely came from trailers rather than power units.
• Make the extra effort to check the pressure on the inside dual. If you can’t find the valve stem, get it fixed or report it as an unserviceable tire.
• Request that the fleet install tire-pressure decals for easy reference, or perhaps consider an inflation monitoring system.
• Ask the shop to supply you with a tire pressure gauge, or even teach you the correct method of checking tire pressure.
• Keep track of tire pressures. Truck tires will naturally lose about two pounds of pressure a month just by air permeating the inner liner and going through the tire. Air can also escape between the bead and the wheel, as well as through improperly tightened valves, torn rubber valve grommets, or valve cores that have been blocked open by dirt and ice. Then there are nicks and cuts to watch for.
• Remember what a pain in the neck a flat can be. Stay pro-active.

The benefits of maintaining inflation go a long way beyond controlling tire costs or minimizing hassles. There’s the safety angle, for one, not just your own but the folks you share the road with. And with kicker is fuel economy: run your tires low on air constantly and you’ll spend 2% or more on diesel. Doesn’t sound like much but do the math.

This article originally appeared in the May 2009 issue of Highway Star and is reprinted with permission. - back