Also Nitrogen filled tires lose pressure more slowly, because Nitrogen molecules are larger. The difference is not significant.
That's what they told me at the dealership too. I asked "larger than what? Air is a mixture that's already 78% nitrogen." Didn't get an answer.
As far as the lower moisture content, couldn't they pass the air through an air dryer before filling the tire if it was that much of an issue? Regardless, the outside of the tires & wheels are exposed to far more corrosive materials.
No idea about molecule size, but the reason for nitrogen is that it expands less than air when heated, so tire pressure doesn't change as much when driving hard on a track.
> As far as the lower moisture content, couldn't they pass the air through an air dryer before filling the tire if it was that much of an issue?
Yes, this point is some dealership BS. Pretty much every auto shop will have a dedicated air line for filling tires, if not the whole system with an air dryer.
> No idea about molecule size, but the reason for nitrogen is that it expands less than air when heated, so tire pressure doesn't change as much when driving hard on a track.
Pressure/temperature/volume for any gas are governed by the ideal gas law, which doesn't care what your molecules are.
(Sure, it's an approximation, but certainly one that's imperceptibly reliable enough for car tyres).