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Why are racing car tires filled with nitrogen?
July 10, 2009
7 Comments | Add Comment
You Asked:
Why are racing car tires filled with nitrogen? — Midhun, Palakkad, India
Marshall Brain Answered:
There are supposed to be a number of benefits with nitrogen-filled tires. Everything from fire-prevention to rust-prevention to leak prevention to more consistent tire pressures. This video talks about some of the benefits:
But… a lot of this is snake oil stuff. The effects are so small that they would probably be unmeasurable.
If you fill your tire with normal compressed air, it is about 80% nitrogen to begin with. When you put in pure nitrogen, you are eliminating two things: oxygen and humidity. It could be argued that oxygen and humidity can increase the rate of corrosion, but when was the last time you saw a rusted wheel? Aluminum wheels don’t corrode, and steel wheels are treated to prevent corrosion. It could be argued that a tire filled with nitrogen will leak more slowly than a tire filled with air, but tires leak. You still have to check the pressure periodically and top up. The difference is infinitesimal.
Why are racing tires filled with nitrogen? It certainly doesn’t hurt, and it sounds cool and techy, and there might be some tiny benefit. Who in the world of racing is going to pass up any possible benefit?
Comments
7 Responses to “Why are racing car tires filled with nitrogen?”
Alan Waxman says: nitrogen is a cooling gas. race cars build up a lot of heat in their tires with resulting wear and damage potential not to mention safety. It’s also for the same reason nitrogen is pumped into elecrical systems to keep the heat down and high output tramsmission towers. That’s why you see the familira tank of gas at the bottom of many power poles.
Mat says: Just try nitrogen in your tires once and you will notice the difference! And it is not infinitesimal.
I did and it works great by keeping the pressure nearly the same for months, because I wanted to check their claim (had to, after paying $30!). Like most other people, I rarely ever checked my tire pressure.
My mechanic told me that it is the oxygen which is 10 times more in air that causes the tire to lose air pressure faster.
If you check your tires regularly and fill it accurately, may be you will not benefit much. But, I think, many people will.
Tires filled with nitrogen run as a cooler in the summer and since nitrogen is relatively inert,less corrosive to the innards of a tire than regular air.
This is a very interesting bit of information, because I’ve always read that the difference in gas mileage can’t be measured between oxygen and nitrogen filled tires.
This is definitely something I must research further. Thank you for the info!
I have here the list of advantage in using nitrogen for tires instead of ordinary air.
1.Less inflation pressure loss
2.Reduced wheel corrosion
3.Prevents inner-liner rubber deterioration by oxidation
4.Tires run cooler
5.Increases tread life
6.Increases fuel mileage
7.Helps prevent uneven wear
I would say the main benefit, as far as for racing cars, is nitrogen-inflated tires corrode slower than oxygen-inflated tires. As we all know, racing cars get a lot of wear and tear so it’s important to put in place elements, such as nitrogen-inflated tires, to prevent or slow the corrosion of tires. This also helps to save money for not having to replace these as often.
There is another benefit for racing tires, the rate of expansion is a lot more predictable. When filling the tire with a pure homogenous substance, the expansion rates due to heat are always the same. So a race engineer can specify a cold tire pressure and he can reliably predict what the temperature will be when the tires heat up. This benefit is lost on street tires due to two things, 1.) the temperature change in a street tire is relatively small, and 2.) a 0.5psi change in a street tire has a very small effect, but can have a large effect on a race tire.
Also, any pure substance will work, it just happens that nitrogen is the most readily available.