Back when I did production welding on automobile bodies we would change every morning before we started the day. We had good drag out ventilation, very little smoke. The man fans helped a lot also. At that time I, and a few others would burn up a 35 pound spool of wire in a day.
When I think of car body welding I think of car body tack welding, when I think of tack welding, I think 35 lbs. of wire in one day for tacking is a heck of a lot of wire for tacking= a lot of hand on gun trigger time with out a coffee break, which makes since if your in China........