It's unlikely that it will be worth it to you to fill your Mustang's tires with nitrogen. There’s a lot that’s been written about the merits of inflating tires with pure nitrogen. Some of the arguments for it are that it leaks less and resists changes in tire pressure due to tire temperature. While the latter is true (and the former is unconfirmed), the degree to which it has an effect is practically negligible. That being said, filling your tires with nitrogen isn’t necessarily a bad thing to do; it certainly won’t harm your Mustang. The real issue here is money and time.
Do Nitrogen Tires Make a Difference?
"The issue lies within the water vapor "
Although the air normally pumped into your tires is already around 80% nitrogen, full nitrogen tire inflation will only remove that remaining 20% of ambient oxygen and other various trace gases. The chemical properties of nitrogen itself aren’t what is valuable, but rather that removal of the 20% of non-nitrogen gases. The issue lays within the water vapor that hangs out in the non-nitrogen gasses. As your tires heat up, they heat the gasses within them. When water vapor heats up, it expands. Even though there is a relatively small amount of water vapor inside of normally inflated tires, it can still expand enough to change the psi of your tires. This can either be from erratic swings in ambient temperature or the resultant heat from tire friction. Ultimately, this can cause irregular psi across your tires, or even cause them to pop given that they are overinflated or damaged to begin with.
Does Nitrogen in Car Tires Help?
If you are willing to spend every penny possible in order to improve your performance at the track even in the slightest, then sure, go ahead and fill your tires with nitrogen. However, if you are just looking for a modest handling improvement for your Mustang, nitrogen tires aren’t worth the investment. All Mustangs after 2007 come with tire pressure measurement systems (TPMS) by default, so any erratic fluctuations will come to your attention. Additionally, if you have an older Mustang, you can mitigate the risk of uneven tire pressure by simply staying diligent and checking their PSI frequently.
There are some additional fringe benefits of inflating your tires with nitrogen as well. Since nitrogen is inert, there is an added fire safety bonus of not having tires chock-full of flammable oxygen. Additionally, the lack of water vapor in nitrogen-filled tires does limit any corrosion that could occur on the wheelbase from water vapor.
Are Nitrogen Tires Worth It?
Again, while there are slight benefits to nitrogen inflation, they don’t justify the cost for the vast majority of Mustang owners. Sure, nitrogen is better than air in car tires, but not better enough to justify to the added cost. There is also an added hassle of having your tires inflated with nitrogen, as the process of bleeding out the air in the old tires can take extra time, and make a routine tire re-inflation a significantly greater hassle. Unless you are attempting world record runs, then there is no real reason to inflate your Mustang’s tires with nitrogen.