The LJ has a small tank, can't remember, 1 or maybe 1-1/2 gallon? Something like that.
Doesn't make any difference in tire fill times. Does let the compressor just run while moving between tires, or whatever, without tripping the pressure switch or dead heading. Does give a one time whoosh, which has been useful only a couple of times. Once for an air hammer to knock a busted TRE stud out, once seating a bead with a ratchet strap.
Over all, I'm glad the tank is there though. It doesn't eat anything. And provides some benefit.
- DAA