@consigliori !
Every engine and its ECU software behaves differently, do not compare it with SUV's.... i even experienced exactly the same back to back in my Civic and Grande, both do the same like you said. This is because if momentum speeds up at a descend than the CC set point, despite reducing the fuel at bare min and pulling off at max it starts deviating. Thats why mentioned in O M book clearly that do not use CC on up/ down hill i.e. moderate to steep ascending and descending.
The reason is it deviates during descend and put extra strain on trany during ascends.
On tolerable ascending and descending this is nornal to deviate a little bit like you and me experienced.
