The other day I was down to the Dodge Dealer and was eyeballing a new apparatus there. It is a "machine" for servicing vehicle tires with nitrogen. I talked to the service people and they gave me a brochure to read and told me it would cost about $50 to service all four tires. It appears that the advantage of nitrogen over air pressure is that the nitrogen doesn't escape through the side walls of tires like air does. Has any body done this to their RV tires? So, other than having a tire failure one wouldn't need to monitor the pressure in their tires, or so it would seem. MY SIL tells me that the Costco in KC, KA only services new tire sales with nitrogen at no cost. I would consider it but I have no idea how I could get my rig into the lot to get access to the machine. OP