Radar Cruise uses engine braking?

[GoISU]

So on a drive today I tried out DRCC while descending a 6% grade. I brought the LC to 60mph as we started heading down the grade then quickly changed the DRCC speed setting to 50. Then I watched as it stepped through 3 gear changes to create enough engine braking to bring the speed down to 50. Shifts were about 5 secs apart. Clearly doing downshifts to control the speed. Now I don't know if it would do that when slowing down due to encountering a slightly slower vehicle in front. But it suggests that using engine braking and even downshifting to create it is something that it can do to control speed.

That sounds like some legit evidence. The fact that it will shift to adjust the speed is indicative that the transmission is a part of the speed management system vs just doing what the throttle input is doing relative to speed.

I run the truck in ETC mode sometimes and the mode holds gears and shifts quicker to improve responsiveness I believe. Sometimes when I lift off the gas the sensation of the holding a gear can be felt. It’s very similar to the RCC when slowing at times.