This may not be a correct response to your question, but I know that if you do wish to keep it in 5th gear on the highway and are in cruise and have a sport, simply leave it in manual mode, with paddles engaged and put it in cruise, the only thing it will do is unlock the torque converter for some hills. I have heard though that engine RPMs aren't half as important as throttle position and since CC is designed to be the most economical, this could be a reason they engineered it this way. It's not a throttle position based CC at all, it's based on speed solely, believe me I live in CA, LOTS of hills and it does great on them! Just don't be afraid to let it rev your engine, it's a Honda