I thought this may have been posted somewhere else, but I'd be darned if I can find it anywhere. Driving an '07 Silverado with the new body style (if it even matters), and it's got this nifty thing that GM calls "Automatic Transfer Case". What on God's good Earth does the auto function do? I fully understand the functions of 2 and 4 wheel drive systems, when to use them and when you can royally eff up the transfer case. I've asked around some shops, and one guy said the auto function engaged the front axle and transfer case but didn't supply more than a few % of the available torque from the engine until the rear wheels began to slip. Another shop told me that it only engaged the front axle if it sensed wheel slippage in the rear and it was a strait 50/50. A third shop told me that it pulsed the gears in the transfer case to engage and disengage the front axle (with the front hubs locked in), and increased the frequency of this action if it sensed that the front and rear were not at similar rotation speeds. Who, if any, actually knows what really happens? I ask because I put about 450 miles on it a week with my new job, and you don't call in just because it snowed the night before. it'd be good to know what my truck is doing before I need a new pair of skivvies. Additional information, the description of the auto setting from the owners manual reads as follows, and no it's not a typo: "AUTO (Automatic Four-Wheel Drive): This setting is ideal for use when road surface traction conditions are variable. When driving your vehicle in AUTO, the front axle is engaged, but the vehicles power is sent only to the front and rear wheels automatically based on driving conditions. Power is sent to the front and rear wheels automatically based on driving conditions. driving in this mode results in slightly lower fuel economy than Two-Wheel-Drive High." If I had to guess what happens, is it's some sort of variable torque transfer case (because it's not really a differential) and it applies more up front only as needed? If it didn't, I could see the same issues happening as if you drove on pavement without the center differential. Am I seeing this right, or just wandering lost through the woods on this one? Thanks guys!