Originally Posted by FordRoushFan
That's the true internet way! Shout out your answer without any evidence or proof to back it up.
Pure nitrogen in your tires is better than just compressed air if it was just a straight up toss up of one of the other. As stated before, yes nitrogen is a bigger molecule, so it won't escape as easily as all the other elements in regular compressed air like oxygen. But it's real benefit comes from temperature spikes. It's pretty good at just being nitrogen and not expanding or contracting or freezing. So places like here, where it goes from +40 to -40, it's obviously a good choice. But air has elements that don't react so well to those temperature spikes, especially in terms of water, (humidity in the air). So you can get a rougher ride (noticed on cold mornings) and different tire pressure depending on the temperature. Which can lead to faster wear.
I've never paid for nitrogen, as I always get it free so why not. But if it were to cost you like 20 bucks a tire, don't bother with it. Especially on used tires. Save that 80 or 100 bucks and put a down payments on new tires.
Protip, put the new tires on the back and you'll get a more even wear pattern after a year. Assuming the front still have good tread that you can steer with.