Quote Originally Posted by vlad View Post
From experience/experimentation with previous KS and the current car. Because a driver can monitor road condition and adjust throttle better than CC. On a straight flat highway with little traffic and inexperienced driver, than the CC will be better.
In my experience, cruise control makes no difference to fuel economy compared to a carefully-driven car not using it under the same conditions. For most drivers, the real advantages of cruise control include: (a) more consistent speeds (except in hilly terrain); less risk of incurring speeding fines. Regarding (a), this could lead to either higher or lower fuel consumption, depending on what your average speed would be without cruise control and how often you deviate from that.