The advantages of nitrogen tire inflation have been understood for many years. But there still is much debate as to the magnitude of those advantages, and as to whether filling up with the gas can provide your customers with a return on investment.
DIFFERENT BEHAVIOR & PERFORMANCE
Proponents of nitrogen will tell you that the gas has larger molecules than air, so migration through rubber is slower, and tires stay properly inflated longer. They also correctly note that nitrogen is drier than air, so corrosive moisture is reduced. And, since moisture holds heat, a dry tire should run cooler. Finally, nitrogen doesn’t expand and contract, or vary as much in temperature as air, so it’s argued that tires maintain a more consistent footprint, thus improving wear.
THE PROS
In a previous position as president of Roadway Tire Co., Peggy Fisher, now president of TireStamp, was keenly interested in nitrogen inflation for the reasons noted above. “A nitrogen-filled tire will lose only about two pounds per square inch (psi) over six months, as opposed to losing that amount in two months using air. Also, the moisture in air can attack a tire’s belts as it passes through, causing the casing to lose retreadability. Moisture in air also can attack wheels, creating small particles that can lodge in valve seats when a tire is aired or gauged.”
The problem with nitrogen back then was that nitrogen generators were very large and extremely expensive. “They were almost the size of a small house,” she recalls. “If I’d had today’s technology, I definitely would have tried it.” With today’s smaller, more affordable generators, testing to prove nitrogen’s benefits now is feasible, she says. If in her old position today, “I’d be doing it.”
THE CAVEATS
“To get the benefits of nitrogen, it has to be pure,” says Asa Sharp, OEM & national account executive, International Marketing Inc. “Tests have shown that you need 95 percent nitrogen in a tire.” The problem, he says, is make-up air on the road, where nitrogen probably isn’t available. “You can negate the benefits with as little as 10 percent air.”
Moreover, Sharp doesn’t believe reduced sidewall permeation is as important as it was 15 or 20 years ago. “Over the years, tire manufacturers have upgraded air retention through the use of barrier liners and new bonding techniques,” he says.
Tim Miller, marketing communications manager, Goodyear Tire & Rubber, agrees that the biggest problem with nitrogen is make-up air. “It defeats the purpose,” he says. And, as for nitrogen’s absence of moisture, “I think you can get the same benefit by using dry air.” That requires only the addition of an air dryer to a dedicated airing line.
