Downshift on icy road?

Wentwest, you have hit it spot on. The trouble with the experimenting is that the conditions have to be exactly the same every time to do a valid comparison, and you have to do the experiment over and over to account for tiny differences in speed, brake pressure, etc. That’s what makes it so tough. At least if I could get to someone who really knew how the system was designed I could start with a more educated guess.