With sheet metal it will be fine. Your travel speed and wire speed can compensate for the non adjusting voltage or amperage setting. Just make sure it's penetrating correctly. If your doing any frame work then crank it up and be sure your doing it right. I would suggest a root pass on a frame and then cover it with filler welds and that would be good. That is used a lot with stick welding and no reason it will not work with MIG.