Totally agree with engine braking. When going down the mountain grades I use the gear that will keep at or below my desired speed. I have the chevy exhaust brake or what ever it is now and it helps a ton. But when I didn't I kept total control with the gear down tactic. I learned it the hard way when we just about completely lost our brakes in a 1988 27 foot jamboree class C, going down some real steep mountain grades, I think by Yellowstone. I was seriously considering turning into the mountain because my brakes were about completely gone and we were on never ending desending switchbacks. I thought I was being careful and not riding the brakes. The local mechanic came out and bled my brakes up on the mountain. He said he was up there all the time. For just that reason. He is the one who told me you should really use your brakes hardly at all while descending with a heavy load. He also said if you are going fast down a mountain with a heavy load and more less have to make a panic stop. The second time you try you may not have brakes. I continued on our trip and used his advice and really barely touched the brakes on steep descents, I let the tranny do all the work. Worked great. Nothing like the feeling of you brakes going to the floor with the whole family in a RV going down a winding mountain grade. YIKES