The facts about nitrogen filled tires
More and more vehicles are being sold with nitrogen in their tires compared to having the tires filled with compressed air. Is this the way of the future when it comes to our vehicles? Are there any advantages or disadvantages to using nitrogen instead of compressed air? Well, I’m glad you asked.
Nitrogen is less likely to leave through the tire rubber than compressed air would. This means your tire pressures will remain more stable over the long term. Passenger vehicles can benefit from the more stable air pressures. But there’s more that drivers should be aware of. Some air pressure pumps will carry water inside it, usually in a vapour format. This humidity (water) is not a good thing to have inside your tire. Water, whether it’s present as a vapor or as a liquid, can cause more pressure changes with changes of temperature than dry air does.
When the tires lose pressure it can become a serious vehicle handling issue. An underinflated tire has less tread making contact with the road surface. This reduction in traction can seriously affect the way you brake and steer. Not only that, those spots on the tire wear down quicker than the rest of the tire and that uneven wear means new tires sooner.
Tires are generally inflated with compressed air which is a combination of roughly 78% nitrogen (N2), 21% oxygen (O2) and 1% other miscellaneous gases. Here’s a fact: all gasses will expand when heated and will contract when cooled. Tire inflation pressures tend to rise and fall with changes in outside temperature by about one PSI (pound per square inch) for every 10° Fahrenheit, or 6° Celsius, change in outside temperature. For these reasons, it’s recommended you check tire pressures early in the morning before temperatures really change significantly. The natural radiant heat of the sun or the heat generated by driving can actually cause the tire pressure to increase.
Pure nitrogen has been used to inflate tires because it doesn’t support moisture or combustion. The challenge facing filling your tires with nitrogen has been its method of supply and cost.
So, is it worth it to inflate your tires with pure nitrogen? If you can go somewhere that provides free nitrogen, then absolutely. However, many service providers are offering prices around $5 per tire to a less reasonable $10 per tire or more to fill your tire up with pure nitrogen. Some service providers provide air compressors for free or you may have to pay a few coins to fill up all of your tires.
However, rather than paying extra for pure nitrogen, you would be better off buying an accurate tire pressure gauge to allow you to check each tire pressure regularly. Fuel economy will depend on how well you can maintain proper air pressure in all four tires. It doesn’t really matter what type of gas is in the tire. If the tire is properly inflated, the fuel economy will be consistent.
Thank you, thank you. I’m a big proponent of testing tire pressure on a regular basis. Air over Nitrogen has never been an issue for me. My experience is that most leaks occur as a result of tire damage from road hazards (nails, screws, misc debris) or corrosion at the tire valve. The vast majority of leaks are going to occur whether you have compressed air or pure Nitrogen in the tires. The answer to tire leaks and safety in general is simple preventative maintenance, in other words walk around your car, look for issues, check lights, tire pressure, pop the hood and check fluid levels at least once a week. It takes minutes and can save you hours of delay on the road.
Thanks again Scott for a common sense post.
Great post! I thought about this a while back as I was going to inflate my tires and remembered they were filled with nitrogen when I purchased the tires. Then I realized air is primarily nitrogen anyways, so I just filled them up anyway. Never considered the moisture component, not sure how you would prevent that.
In regards to your statement on under-inflated tires, they actually increase traction as more tire surface area is in contact with the road. That is why rock crawlers let air out of the tires, to increase traction. Under-inflation leads to increased friction and heat which can cause increased tread wear, tire failure, and blowouts. An over-inflated tire would reduce traction as it reduces surface area.
The tyres on my classic motorcycle have inner tubes and do tend to lose presssure, so I check them regularly. It’s of note that the (tubeless) tyre pressures on my modern motorcycle and my car remain more constant, but I check those as well. None of them are nitrogen filled though. I’d be curious on the percentage of vehicle owners who actually know what pressures their tyres are supposed to be at, but I suspect that it’s a low number.