Inflating your tires is one of those no-frills maintenance jobs that’s just a fact of life for every driver on the road (or at least, it should be). But has it ever crossed your mind regarding what you’re pumping into those tires? Probably not, because for the vast majority of situations, it’s plain old air.
But how about nitrogen? You may have heard of it being used in car tires from time to time in the past; its most famous use is perhaps the R35 Nissan GTR, first introduced in 2007. The GTR is, of course, primarily a driving-focussed car, so let’s explore why it uses nitrogen, and why you too may want to use it in your BMW.
First thing’s first, we need to quickly clarify that nitrogen is not some kind of unstable exotic gas that will blow up your whole car if you just so much as look at it in the wrong way. In fact, as I’m sure most of you know, the air we breathe in all day every day is mostly made of nitrogen, anyway. So what happens when you remove the oxygen, carbon dioxide, and traces of other gases from the mix?
The main benefit of having nitrogen in your tires is that your pressures will remain at an ideal level for longer. Tires inflated with normal air typically lose a small but noticeable amount of pressure over time, which means they need to be topped up every month or two. Nitrogen molecules are larger than the oxygen molecules that they replace, and therefore are much less susceptible to leaking through the inner lining of the tire itself.
A tire that maintains pressure for longer gives a safer and more consistent driving experience behind the wheel and also ensures that your fuel consumption stays at an ideal level, and doesn’t get pulled down by the drag of under-inflated tires. But are there any benefits of nitrogen tires for the more spirited BMW driver?
As it turns out, yes there is. Pure nitrogen is an inherently very stable gas, and as a direct knock-on effect from that, nitrogen in the tires is very resilient against temperature changes that come from hard, enthusiastic driving. Ultimately this means that your steering feel should remain consistent, predictable, and reliable no matter how much you wish to push your pride and joy down the road – that can only be a big positive.
So we’ve established that nitrogen tires can have good benefits for your BMW, regardless if you wish to drive economically or enthusiastically. But what about availability, or the dreaded potential cost?
In truth, nitrogen inflation is not something that’s readily available at the vast majority of self-serve petrol stations. Chances are, you will have to book into a garage, and most garages charge a premium over standard air. So while nitrogen does carry benefits, it’s worth bearing in mind air is 79% nitrogen anyway, and is way more accessible. Nitrogen may bring some performance enhancements, but then again, so would regularly keeping on top of your air pressures, so choose wisely.