The other day we had the SPEED channel on in our waiting area and there was a show on the TV where they were making recommendations about various cool ways to modify your car. One of the things they mentioned was the benefit of filling your tires with nitrogen instead of air. I have always filled my tires with air and don’t have any problem checking and refilling them when necessary but every now and then people will call or come in to TEXAS TIRE SALES and ask if we offer Nitrogen Inflation. We decided to provide a little food for thought as to the benefits… or not, of putting Nitrogen in your car’s tires. Is there really a benefit or this just a way for tire dealers to squeeze a few more dollars out of the customer? You decide.
Sure, there are some benefits to putting Nitrogen in your tires: (1) Awesome fluorescent green valve stem caps signifying that “these tires have Nitrogen in them assuming that your tire store’s nitrogen vendor has any amount of marketing savvy. (2) Bragging rights. OK, you maybe you were behind the curve when it came to texting, Face Book, or maybe you haven’t bought your first hybrid car yet, but, you’re in luck. Inflating your tires with nitrogen is a fairly new concept to most people so HERE is your chance. (3) There will be greatly reduced fire danger next time you are landing your commercial aircraft, since nitrogen doesn’t support combustion. However, unless you have some very Extreme driving habits, the chances of your tires catching fire driving around town are very slim.
The truth is, most tires are filled with compressed air, which when dry consists of about 78 percent nitrogen, 21 percent oxygen, and 1 percent other gases. Unless you live in Las Vegas, water vapor (humidity) can make up as much as 5 percent of the volume of air under worst-case conditions. Filling your tires with nitrogen mainly does two things: it eliminates moisture, and it replaces thin oxygen molecules with bigger nitrogen molecules, reducing the rate at which compressed gas diffuses through the tire walls. That means, theoretically at least, that a tire filled with nitrogen retains optimal pressure longer, leading to more even tire wear and better gas mileage.
On September 20, 2006, Consumer Reports decided to determine if nitrogen is worth the price, so they purchased a Nitrogen Inflation System and checked out how well the inflation held up over a one year period. They evaluated pairs of 31 tire models of H- and V-speed rated, They filled one tire per model with air and the other with nitrogen. The test was fairly simple: fill and set the inflation pressure at room temperature to 30 psi (pounds per square inch); set the tire outdoors for one year; and then recheck the inflation pressure at room temperature after a one year period.
The tires were filled and deflated three times with nitrogen to purge the air out of the tire cavity. They also used an oxygen analyzer to be sure they had 95-percent nitrogen purity in the tire.
The results showed nitrogen did reduce pressure loss over time, but the reduction was only a 1.3 psi difference from air-filled tires. The average loss of air-filled tires was just 3.5 psi from the initial 30 pressure setting. Nitrogen-filled tires lost an average of 2.2 psi from the initial 30 psi setting. The most important conclusion was that, all tires lost pressure regardless of whether they were filled with nitrogen or compressed air.
Something to consider… Nitrogen is non-corrosive dry gas and will reduce oxidation and rust due to the absence of oxygen and moisture. This does help minimize wheel corrosion for those who are still riding on steel rims. As far as Nitrogen being more friendly to the rubber? Tires that are used regularly will likely be replaced long before any life benefit would be received by using Nitrogen. Nitrogen is a dry gas and will not support moisture that could contribute to corrosion of the tire’s steel components (bead, sidewall reinforcement and belts) due to the absence of moisture over extended periods of time. However it’s important to remember that atmospheric pressure is constantly pushing oxygen and moisture into the rubber from the outside of the tire.
Nitrogen inflation may be most beneficial for extremely low mileage drivers who don’t wear out their tires quickly or those that run average annual mileages but use long wearing radial (60K and 80K warranted) tires. Nitrogen inflation is likely most beneficial for those who drive their vehicles infrequently (car collectors, race track drivers, snow tire users, motor home owners, etc).
Overall, filling up your tires with nitrogen won’t hurt and may provide some minimal benefit but is it worth it? There are a few places that provide Nitrogen inflation for FREE and if you are at one of those places buying tires of getting tires repaired then sure, why not?
Elsewhere, though, We’ve seen prices quoted as high as $10 per tire, which is way more than we would recommend that anyone pay. Rather than shell out the extra bucks for nitrogen, you’d be much better off just buying a good tire pressure gauge and checking and adjusting your tire pressure regularly, something the National Highway Traffic Safety Administration says less than 60 percent of U.S. motorists actually do. They also remind us that the single most common cause of tire failure is under-inflation.