I'm curoius about the 2012 Active ECO mode, and what it does to improve MPG. This morning while driving in the hill country of north Georgia I think I discovered one parameter of the Active ECO algorithm. Under normal circumstances while driving with Cruise Control, the speed is controled within + or - 1 mph of the target speed. When using Cruise Control with ECO selected, Cruise Control will allow gravity to increase the downhill speed significantly above the target speed. This morning I observed downhill speeds 5 mph over the target speed, without Cruise Control making any correction.