KansasGM

Hi all, Have a question regarding downhill engine braking. My Dad has a 2015 Sierra All Terrain with the 5.3/6 speed, 3.43 gears. Engine braking is phenomenal. We can pull a 5,000# load through the mountains, and the engine braking works perfect to where we don't have to use the brakes basically at all. I have a 2018 Silverado with the 5.3/6 speed. It has the tow package so 3.73 gears. Engine braking performance is not good at all. I have to use the brakes several times when towing going downhill. I can manually control the gears to keep it revving 4,000 or more, but it will just keep speeding up until I hit the brakes. The only difference I know of is I have a Range device plugged in keeping it in V8 (I have vibration issues if I let it go to V4). Was there a programming change or something from the years between 2015 or 2018? Does anyone know why there would be a difference in engine braking? Thanks