So when I first bought my 07, it was in auto and thats what I thought it stayed in...well needless to say a year later, yes, a year, I needed to change the transfer case fluid. But yes, like david said, 2wd at all times, unless you have snow or the roads are slick, frozen rain, packed snow, etc you can use auto. I only use 4hi in deeper snow. And rarely do I use it. Tahoe handled 6-7 inches just a few days ago just fine in auto.