I've been using 75/25 because I had 1/2 a bottle to finish up. Works well on pulse but a little more splatter than I would like. I was going to get the 90/10 as reccomended for pulse but dont know how well that gas works in mig mode. I've been using pulse almost all the time & like it a lot but would still like to be able to use mig mode. ( referring to mild steel work)