Tow mode also activates the airbags in the suspension. I forgot about the shift points. I turn on tow mode when loaded up with gear (like ski gear, camping gear etc.) even if I am not towing. This stiffens the rear suspension and lessens the wallowing effect when going over abrupt changes in the road (like bad sections of freeway, or other bumps that give you the wallowing Caddy feeling). Also, there are a few roads where they "wallow" you around so much (West Lake Sammamish Parkway, if you live around here) that tow mode stiffens the ride and lessens the wallow.