Should I Put Nitrogen in My Tires?
Using pure nitrogen can be pretty effective in extending the life of your tires, rims and your vehicle in general — but that doesn’t necessarily mean you should run down to your local service station and pay to start making the switch right now. In order to understand what’s good about nitrogen, we need to understand what’s bad about air.
Wait, The Problem is The Air?
Kind of. What you may not realize is if you put air in your tires, you’re using mostly nitrogen already. Strictly speaking, the air around us is a chemical combination of nitrogen, oxygen, carbon dioxide, water vapor, and other trace elements — but nitrogen makes up a hefty 78% of that mixture. As race-car drivers figured out early on, it’s the 22% of other stuff like oxygen and water vapor that make having a stable inflation pressure problematic. Oxygen and water vapor especially are much more sensitive to changes in temperature than nitrogen, meaning that as they expand and compress more frequently it can be difficult to maintain a tire’s proper PSI. Over time, that’s can lead to a reduced fuel economy.
There’s also the problem that oxygen and water vapor will move through the porous rubber in tires — whereas nitrogen to a much greater extent will not — which can exacerbate corrosion on both steel and aluminum rims, as well as of course lowing the pressure in your tires.
So Why is Nitrogen Better?
Pure nitrogen is better to have in your tires not so much because it’s nitrogen, but rather because it isn’t water vapor or oxygen. Any system that pumps nitrogen into your tires will repeat the process over several iterations, depleting any moisture from the tire as well as oxygen, CO2, and the air’s other trace elements. Because the gas isn’t as receptive to changes in temperature and it won’t migrate through the rubber, when you use nitrogen your tires will stay at stable pressure longer.
…But we aren’t all race-car drivers. Chances are, your tires aren’t really experiencing the grueling, high-temperature conditions of a speedway–so on a normal roadway, your car probably will still feel like it rides the same, or with only a negligible improvement. While nitrogen is chemically proven to sustain pressure better than air, and you will save a small amount in fuel economy and maintenance costs, with many dealerships charging $30.00 per tire or more, it simply may not be worth the investment.
Short answer: If someone offers to put nitrogen in your tires for free, don’t say no. Otherwise, you’re probably okay.
March 8, 2012 by Jamie Rettig