Nitrogen in car tires, yes or no.
To be quite honest, I have nitrogen in my tires. Never again. I bought new tires, had nitrogen put in them. For some odd reason, they tend to leak just a little.
Since 80% of air is nitrogen, the only gain for going to 100% would be to possibly reduce oxidation inside, which the tire composition guards against. There is not enough change in density to improve heat flow if you needed it.
