Is putting nitrogen in your tires a waste of money?

What you need to know if you’re trying to choose between regular air or that fancy air

By Jens Nielsen

The question of whether nitrogen is a good thing or a scam comes up a lot both at dealerships and on the internet.

The main function of your tires is to carry the weight of your vehicle. It’s not actually the tire that carries the weight, but the air inside the tire. This becomes very clear when you get a flat tire.

As I have written about in previous articles, ensuring the air pressure in your tires is always correct helps keep the tires performing properly, helps them last longer, and improves fuel economy.

Normal air is approximately 78 per cent nitrogen, 21 per cent oxygen, and about 1 per cent other gases. These gases tend to expand or contract depending on the temperature by about one pound per square inch per 6 C. This is why your tire pressure can change throughout the day and should be checked in the mornings before driving. Your tires can also lose one PSI per month just from normal driving.

The compressed air you use to fill your tires often contains varying amounts of moisture. As this moisture builds up over time in your tires it can affect the health and longevity of the tire.

Race car drivers began using pure nitrogen in their tires to help eliminate changes in tire pressure and moisture. NASCAR, the airline industry, NASA, and the U.S. military have all used nitrogen-inflated tires for years.

Nitrogen providers list a range of benefits to using nitrogen over regular air. These include less air pressure loss, longer tire life and better fuel economy. These claims are largely based on stats that say only 85 per cent of people check their tire pressure regularly and 54 per cent are driving on at least one under inflated tire. They also point out that nitrogen permeates tire walls up to four times slower than air. So instead of tires losing one to two PSI per month it takes over six months to lose same amount of pressure.

Providers also suggest that nitrogen may actually enhance the reliability of your tire pressure monitoring system by minimizing moisture and oxygen in the tire and extending the life of your sensors.

Nitrogen may offer the additional benefit of no flat spots on your tires on cold mornings.

Nitrogen service equipment manufacturers have developed small, on-site nitrogen generator systems that separate oxygen and moisture from the shop’s compressed air lines to capture the nitrogen. Because there is a cost to these systems and it takes time for a technician to hook the machine up to your tires, the shop would need to charge you for this service.

So should you go with nitrogen or keep the air in your tires the way it is?

It seems to depend who you ask. There are passionate views both for and against nitrogen. Everyone seems to agree that there is no harm in going with nitrogen and there are some benefits to it. The question that comes up is whether the value is greater than the cost.

The cost seems to be all over the board. Sometimes it’s complimentary as part of a maintenance package, sometimes it costs as much as $199. At that price, you might want to pass.

If you were to purchase an air compressor, check your tire pressure weekly, and top off your tires yourself, then you would likely not need all the benefits nitrogen seems to provide.

The other thing to consider is whether the nitrogen will be available to you after the initial filling. You can add regular air to tires that have nitrogen in them, but this will dilute the nitrogen and the benefit.

So, is nitrogen a good thing or a scam? Ultimately, it depends on what it costs.

Catch Driving with Jens on CHON FM Thursdays at 8:15. If you have any questions or comments you can reach out to Jens Nielsen at drivingwithjens@gmail.com, or on Facebook or Twitter: @drivingwithjens.