Why are race car tires filled with nitrogen?

We all know that race cars tend to be very different from your average family saloon; they have different tyres, more powerful engines (obviously!), no need for rear seats and no much trunk space. So it won’t be surprising to hear that they even fill their tires with a different gas. You probably fill your tires with air. That’s a mixture of oxygen, carbon dioxide, nitrogen, and small amounts of a few other things. Racing car tires are filled only with nitrogen.

Nitrogen expands and contracts at a more uniform rate compared to standard air. Considering the speeds race cars tend to travel at, any small change in tire pressure will have big effects on both traction and handling, which could easily change the outcome of a race! When racing lasts a long time (such as Formula One or Nascar racing), track temperatures can vary considerably, so consistency of nitrogen pressures can make a big difference.

Why does nitrogen hold its pressure so much better than normal air? To begin with, air contains small amounts of moisture. The exact amount varies throughout the day depending on weather conditions, and even small amounts will lead to significant changes in tire pressure during tire installation during the race, or in the same car but on different race days. race. The driver needs to know how the car will be handled to get the most out of it, so dry nitrogen is used instead.

Interestingly, nitrogen is also used for similar reasons in aircraft, where it is of the utmost importance that tire pressures do not vary too much with different external conditions. An airplane traveling at different heights will be surrounded by air at different pressures and temperatures. In fact, the temperature can drop as low as -40°C, so you don’t want any moisture in the tires as it will freeze and cause problems when landing.

Is there any reason why you would want to fill your own car tires with nitrogen? There are definitely benefits, so it’s up to you to weigh those benefits against the costs and make your decision. The lack of moisture in the nitrogen results in less corrosion on the wheels, and since the nitrogen molecules are larger than the oxygen molecules, the tires will hold their pressure longer. The downside is that you will first need to empty your tires of air before filling them with nitrogen, and to maintain the benefits, they will always need to be recharged with nitrogen.