Has it ever occurred to you to fill your tires with anything other than air? Because nitrogen is more stable than oxygen, it is commonly used in vehicles that require precise tuning, such as race cars, industrial machinery, aircraft, and spacecraft. That makes some drivers think that nitrogen is a better choice for their daily driver and there could be some truth to that. However, whether or not that’s true for your car depends on a number of factors.
Consider that the air we breathe is 78% nitrogen, and a nitrogen-filled tire is about 93 to 95% nitrogen. In other words, the difference between a regular tire and one filled with nitrogen is minimal. How much can that nitrogen work for you?
Let’s look at the pros and cons of using nitrogen in your car’s tires.
Pro: More Consistent Handling
Don’t get too excited. Nitrogen in your tires does not have the power to make your car handle better than it was actually designed to handle, and the advantages are minor for everyday driving. However, nitrogen can help optimize your car’s handling and perform up to its limit by helping stabilize your tire pressure. That’s why race cars use nitrogen in their tires. Most drivers will never notice the difference during their daily commute.
Pro: Reduced Wear and Tear
Filling your tires with nitrogen can reduce wear and tear on the wheels and perhaps other components, as well. Air contains water vapor, while nitrogen does not, and that water vapor will increase the pressure in your tire as it heats up. It’s also common for gas station air compressors to have water in the hose or in the tank, which will then end up inside your tire and add even more water to the mixture.
Water vapor can cause rusting inside the wheel or the valve stem, and can also corrode the sensitive sensors used by cars equipped with tire pressure monitoring systems.
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Pro: Less Leakage from Tires
Air escapes through the tire’s molecular structure as the rubber flexes and stretches while rolling. An atom of nitrogen is a tiny bit bigger than an atom of oxygen, and therefore less able to permeate rubber and escape from a tire.
The math is complicated, but the deal is that air escapes from a tire 1.6 times faster than nitrogen. Keep in mind, however, that even if you have nitrogen inside your tires, you can’t control the oxygen in the surrounding atmosphere, which is still affecting your tires from the outside in.
Pro: More Consistent Fuel Economy
Having the correct air pressure optimizes your fuel economy. Higher tire pressure results in better fuel economy because it reduces rolling resistance, and because nitrogen stays in your tires longer, you won’t have to work as hard to keep them properly inflated, making it easier to get your best fuel economy.
However, if you’re good about adding air to your tires regularly, you won’t notice a difference.
Nitrogen is more expensive than air, and it’s not available on every corner like the trusty air compressor at a gas station. You’ll need to track down a tire shop or a well-equipped service station. If you can’t find nitrogen while you’re traveling, you’ll have to use regular air, which will dilute the nitrogen already in your tires.
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Con: More Time Consuming
Filling up with nitrogen is a little more complex than topping off your tires at the gas station. To maximize the benefits of your nitrogen fill-up, you’ll want to fill and bleed the tires several times to purge as much air as possible. Many tire shops have a machine that will filter oxygen out of the nitrogen and automate the purge/bleed cycle that is necessary if you are filling tires with nitrogen for the first time, but it will still take a little time and you’ll pay for the privilege of using it.
In 2009, it could cost up to $30 per tire for a shop to fill your tires with nitrogen, according to Popular Mechanics, but costs have since come down. Still, depending on where you live, you should probably budget at least a few bucks per tire. Nitrogen equipment is more expensive than the cheap (or free) air compressor at your local gas station, and it also requires the time of a staff member to operate. (Note- Nitrogen-filled tires have green valve stem caps).
Con: You Might Still Need to Add Nitrogen Anyway
According to Tire Rack, nitrogen-filled tires are no guarantee that you can coast through the year without checking and adjusting your tire pressure. You might be able to get by a little longer, but chances are good that you’ll still need to add nitrogen in fall and winter when temperatures drop. And don’t forget, topping off with nitrogen can be a bit less convenient than simply heading to your closest gas station.
When you’re deciding whether or not to switch to nitrogen, it helps to temper your expectations. You’ll never achieve 100% nitrogen purity, but you’ll reap the rewards at the typical goal of 93 to 95%. Whether or not it’s worth it, financially, depends on how convenient it is for you.
Tire Rack thinks nitrogen is worth it when it costs about $5 per tire, but if prices approach $10 per tire, it becomes more expensive than it’s worth. Then, it makes more sense for most drivers to simply pay more attention to maintenance. In summation, rather than pay extra for nitrogen, most drivers would be better off buying an accurate tire pressure gauge and checking and adjusting their tire pressures regularly.