I saw a banner in our local Costco about nitrogen Filling the tires. It said something about better ride and MPG etc. Has any one tried it? It sounded interesting.

Compressed atmosphere (air) has moisture in it which will change tire pressure more when heated than dry nitrogen. It would not be noticeable under normal conditions. Maybe if you had a Corvette or motorcycle doing a track day it might be worthwhile.

I noticed the same thing when a got a set of Cross terrains there for a Grand Cherokee. When I posted that on a Harley forum i got a lot of feedback. Turns out it is more associated with a/c and trucks and corrosion. Turns out regular atmosperic air is 80% nitrogen to start with.

Aircraft use nitrogen for their tires, mainly because of the extreme temperature changes. I don't see a need for this on an SUV.