We went on a short road trip last weekend. And as is usual, we stopped at a petrol pump for fuel and tyre pressure check. But, something caught my eye at the petrol pump and I had to step out and click the picture (that you see in this post). What do you find interesting in it? It could be the bright color scheme or the text (that I am still trying to figure out) or the photo of the cool car. For me, it was the option to fill the tyres with Air or Nitrogen.

You may know that Air itself is composed of almost 70% Nitrogen. So, why do you think the option to fill the tyres with 100% pure Nitrogen is being offered? Just so you know, this is not a new offering, its just getting more popular. In fact, all race cars have their tyres filled with 100% Nitorgen.

Let me explain the growing popularity of Nitrogen by stating why Air isn’t always the best choice for the tyres. Air invariably contains a significant amount of oxygen and water vapour. When we drive a car, the temeperature of the tyres increase due to friction between the tyres and the roads. This increases the pressure of the gas inside the tyres as predicted by the Ideal Gas Laws (one of the most exciting topics that we explore with the middle school children). In other words, just driving the car changes the tyre pressure. This is not an issue in most cases, but imagine a racing car that drives at over 300km per hour!

The tyre temperature changes significantly due to the increased friction, which in turn changes the tyre pressure significantly. This can be disastrous at such high speeds and it is critical to prevent any changes to the tyre presssure. Pressure changes in tyres filled with pure Nitrogen are much less as compared to tyres filled with Air, which is a mixture of many gases. The second cultprit in Air is the water vapour that reacts with the metallic rims over time and corrodes them. Dry Nitrogen, being an inert gas, doesn’t react with any of the surrounding metals/ rubber and increases their longevity.

So, Nitrogen filled tyres definitely offer an advantage in high performance vehicles such as race cars or aircraft tyres. But for everyday travel and even long road trips, the air-filled tyres perform just fine. So, next time, you see the option of filling your tryes with Nitrogen gas, you can give it a pass unless you are planning on participating in the Formula One Race!