Of course compressed air is 78% Nitrogen. You use nitrogen on struts because it's dry so you don't add moisture to the strut. Nitrogen in tires is mostly a waste of money for tires since some moisture and 20% other gasses included aren't going to make much of a difference in the leakage rate.
-Jeff Scott ? ---- Nitrogen is supposed to be better to not slow leak because the molecules are bigger than regular air. I always took that with a grain of salt thinking how much of a difference can it make. A few months ago I helped a neighbor rebuild the nose strut on his 172. He wanted to fill it with nitrogen instead of regular air, but our friends nitrogen bottle was empty. I have a CO2 bottle with a regulator for portable use of air tools and figured that would be as dry as the nitrogen and just as good. We filled the strut and the next day it was empty. Did it again and same results. Googled and found that CO2 has molecules smaller than regular air so we filled it with air and it has been good since. So, how much slower would nitrogen leak than air, no idea, but worth a try. Airline tires are filled with nitrogen for less leakage, more convenient on the line to roll out a nitrogen bottle than a compressor that can go to a few hundred PSI, and less expansion at high temperatures. -------- Original Message -------- Subject: KR> Tire pressure and Slime From: Mark Langford via KRnet <krnet at list.krnet.org> I put all new tubes and tires on 1JF when I refurbed it, and it's had a slow leak ever since on one side. About a month ago I put some Slime in it, and it's still holding 50 psi. Something to consider. _
