inflating tires on rv with nitrogen, good idea?

Costco Tire Center uses nitrogen.

Regular air is 78% nitrogen. On that note, 100% nitrogen won't leak out of your tires as fast as air as the nitrogen molecules are larger. Nitrogen will also maintain a constant pressure regardless of temperature or elevation. I have no experience with nitrogen in my tires, I just carry an air compressor with me.

If you were putting it in an airplane tire or a Nascar ride, it might be useful. In a motor home, it's a waste of money. Some say it reduces moisture issues, but most of todays RV rims are aluminum and it's not a problem. Once you have to add air to any of your tires, you're back to just regular air.

Nitrogen has benefits in tires used for air craft or race cars. For a vehicle at normal speeds, it serves no practical purpose. It is a profit center for the tire seller/dealer.

If it makes you feel better, spend the money on it. It won’t hurt, but remember that it is not as easy to find 100% Nitrogen for bring tires up to pressure.

Normal air contains 78% Nitrogen, so is it worth it for an extra 22%? I think not.

The next time I tow my trailer at 200 MPH or it has the name “Boeing” on it, I will use nitrogen.

Used in airplanes for years, not only in tires but also in struts. The only issue I'd have is finding N2 on the road. I guess you could go to an airport.