Air typically features about 78 percent nitrogen, so why should you pay more to fill your car’s tires with pure nitrogen? Is there a tangible reason to spend more on this or are dealerships and auto shops just blowing hot air?
The short answer is that nitrogen is a waste of time and money and that mechanics are trying to make some money from a problem that doesn’t really exist.
When it comes to your tires, air is a big deal. Air contracts and expands depending on the temperature. For every change of 10 degrees Fahrenheit, a tire’s pressure will change about 1 PSI (pound per square inch). This is why it’s recommended to check your tires on a regular basis.
If it’s cold out, the pressure will drop, deflating your tires slightly, and there’s a chance your fuel-economy might go down too. To resolve this, you will have to pump some more air into your tires. On the flip-side, if it’s hot, the PSI of your car’s tires will increase, and you may get reduced traction or uneven wear of the tire. To solve this, you may need to let some air out of your tires.
Air isn’t the only gas to be affected by the weather like this, nitrogen is just as reactive to the temperature.
“Nitrogen does not replace the need to regularly check your air pressure,” says Lou Trottier, owner of All About Imports a repair shop that sees its fair share of tire-changes. Trottier said he just doesn’t see the benefit of nitrogen for consumers.
Where Nitrogen exhibits an advantage over regular air is when it comes to pressure loss over time. Despite their sturdy appearance, tires actually allow air to pass right through the rubber. Air is made of 21 percent oxygen, which slowly leaks out of a tire regularly. On average, a tire loses about one psi per month.
However, a tire filled with pure Nitrogen leaks less, at a rate that is about one third slower than normal air. This means that if you’re not in the habit of checking your tire pressures often, then using nitrogen wouldn’t be a bad idea. Since the tire would lose pressure at a slower rate, your lazy habits will be absolved.
The reality is, most folks are getting their tires checked on a regular basis, every time they get their oil changed.
If unpredictable air is an issue then water is too. That dingy air pump at the gas station may not be giving your tires the good stuff, and might be slipping a bit of water-vapor into your tire. That’s really bad since water reacts even more drastically to temperature than just air.
In comparison, nitrogen is considered a dry gas, which means filling your tires with it will ensure you won’t get any water in there, making for consistent pressure changes in cold or hot weather, and giving you some peace of mind.
Is It Worth It?
At $10 a tire, filling up with nitrogen isn’t cheap. For the lazy bunch out there, it might be appealing, but certainly isn’t worth it. Besides, checking your tire pressures should be part of your responsibilities as a car owner.
Even tire company Continental has an official stance on filling their tires with nitrogen.
“For normal everyday consumer tire service applications, nitrogen tire inflation is not required,” says a bulletin posted by the company. “The use of nitrogen alone does not substitute for the importance of regularly checking tire inflation pressure.”
But commercial and work trucks fleets have been using nitrogen in their tires for years, why would it make more sense to those operators? The reasoning is scale: ensuring all the tires in a fleet are at the correct PSI means that the fleet’s fuel economy will not fluctuate. Most trucks already don’t have good fuel economy and fleets are spending a lot of money on gas.
As these vehicles are on the road for a long time, they might not get the chance to have their tires checked often. The longer they’re at the optimum PSI, the better their average fuel economy and the less money is spent on fuel over the whole fleet.
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While nitrogen filled tires are more consistent when it comes to pressure and temperature, the better money would be spent on an accurate tire pressure gauge and quality air compressor. As a one-time purchase, these two products will make themselves useful every time you check your tires.