NO2 in tires!!??

I was at the nissan dealer earlier this week to get wheel locks and overheard the parts department talking about getting NO2 gas in the tires of their new frontier?? They said that it cost about $40 and they get great mpg and that it has been standard or something over in europe. Is that for real?? Won't it mess with the tire pressure reading system in the frontier?? Does anybody know about this?