Nitrogen in Trailer Tires

My new travel trailer came with nitrogen in the tires. The drawback is the only places to get nitrogen is car dealerships and a few other places. I have still had to add air to my tires three times this last year. It is not possible to hook up your travel trailer and drive to a dealership when you need nitrogen. I just add air at the gas stations when I need it.

I read once that what they told you is correct. but I do not use that, to me it's a waste of money. as a friend used to tell me. it cuts into my beer drinking money

Atmospheric air is already 70% nitrogen so.....