Tech Tip: Nitrogen Maintains Tire Pressure Longer than Ambient Air

Since 1967, the question of filling tires with nitrogen has captured the imagination of tire scientists and tire dealers alike. Here's what we know: Nitrogen exceeds oxygen in better air retention because nitrogen diffusion through the sidewall is 30% to 40% slower than oxygen. Result: Nitrogen maintains tire pressure longer than ambient air.

Since 1967, the question of filling tires with nitrogen has captured the imagination of tire scientists and tire dealers alike. Here’s what we know: Nitrogen exceeds oxygen in better air retention because nitrogen diffusion through the sidewall is 30% to 40% slower than oxygen. Result: Nitrogen maintains tire pressure longer than ambient air.

We also know that maintaining proper tire pressure boosts fuel economy. By how much is anyone’s guess. Some say as high as 6%; others say a bit less. No matter. By restraining the heat in the tire and reducing rolling resistance, the customer gets better fuel economy, even if that number isn’t as high as 6%.

Nitrogen inflation means a cooler-running tire; just ask NASCAR. With quicker heat dispersion, a cooler-running tire extends tire life and reduces tire failure. Nitrogen also prevents oxidation, which can lead to belt failure. And, when combined with moisture, oxygen can corrode wheels. In fact, moisture can result in rust flakes that can fall into the valve stem, block the valve and cause low inflation. It can even cause the valve stem itself to rust.

For at least 40 years, we have known that a tire filled with nitrogen significantly slows the chemical aging process of the tire’s rubber components. We know that nitrogen-inflated tires result in fewer catastrophic failures, and adds to the tire’s core life. When it comes to big fleets, nitrogen inflation yields extra retreads and lower fleet costs.

We know, also, that nitrogen is not dangerous. It is an inert gas, which means it will not burn.

What maintenance is involved in nitrogen inflation generators?
Simply calibrate the nitrogen generator monthly, and change the filter elements every six to 18 months. Replace the carbon element and oxygen analyzer every 18 to 24 months.

How long will a nitrogen tire inflation system last?
If well maintained, a nitrogen inflation system will last well beyond 20 years.

Can a tire be refilled with air if nitrogen is not available?
Yes, filling a tire with air after it has been inflated with nitrogen won’t cause any problems. The immediate effects of nitrogen will be lost, but the tire will be fine for driving until it can be purged and refilled with nitrogen.

So, what’s the problem? What’s the holdup? Why aren’t more dealers and consumers jumping on the proverbial bandwagon?

Maybe it’s all just a question of getting better acquainted with the technology.