Hi,
I've just discovered that the current ratings for MIGs and those for ARC/ MMA are not nominally equivalent and that MIG ratings have to be higher to match the abilities of ARC. To cut a long story short, what current rating does one need for a MIG to be able to handle the sort of thicknesses of steel you typically find in car bodies? Would 30-90A do it?
90A from an ARC welder would probably blow holes in car body steel, I reckon!