Originally Posted by stuhly
Most tag axles have four airbags on them. Two for down and two for up.
Sorry, but I'm always skeptical when someone says "most do xxx" based on their experience, unless they've worked on hundreds of motorhomes.
My tag (on Freightliner chassis) does not lift, only dumps air. One air bag per wheel position, as far as I know. I leave it set on automatic all the time, pretty much forget it's there. Dumps for backing and low-speed maneuvering, and never scuffs.
To me, the biggest advantage is the huge increase in CCC, of course along with the ability to go longer than 40'.