r2m
Richard
I only drop down a gear or two when on a grade. Highways, I just keep it in full auto mode.I have. No notable change for me. If anything, S is slightly more aggressive and causes it to downshift even more. I haven't tried holding it in 4th or 5th as others suggested. I wouldn't want the MPG hit and engine strain that would cause at 90mph on Texas highways.
Edit: I don't have dynamic CC in my 2019, just the same old Toyota CC with same control knob they've been using for 30 years.
It almost feels like the cruise control software is programmed to adjust speed using the transmission instead of the throttle. So instead of adding more fuel to gain speed, it drops down a gear and keeps the throttle the same.
When we've gone through Texas, I limit my speed to 80 MPH because I'm so heavy and pushing so much wind with the RTT. At 80 MPH trucks with trailers were passing me like I was standing still!