Comming out of Greenville SC towards Atlanta on I85 there are a series of low rolling hills. With the cruise set at the 65 speed limit and watching the tac, the transmission is shifting down to 5th going up the hills after the speed on the nav unit only drops one or two miles per hour. What is unusal is that going down the other side the transmission shifts down to 5th and sometimes to 4th, I guess to provide engine bracking, again with only one or two miles per hour increase. The rig is so smooth you might not notice it unless you watch the tac. I moved the transmission from D to M and it stopped the shifting. I think the cruise/transmission is two tight and wonder if it can be adjusted other than going to M. I would rather the car freewheel or stay in 6th rather than provide engine braking which in the rolling hills is just a waste of gas.