I learned the uncomfortable way to start slow at the top of a mountain. It's easier to maintain than to slow down. I pulled up a mountain in the motorhome pulling the toad. I was feeling great about how well that thing pulled the mountain so at the top I was running 65 or so. Then, all of the sudden, I was staring at what looked like a vertical drop that went on out of sight. Lucky for me there was very light traffic. There was no stopping, just a butt clinched ride to the bottom. I so wish I had been running about 25 MPH at the top. From that day forward I start at the top of every long steep decline at 25 MPH or less and I gear down and keep it down. I'm over with the semi-trucks easing down the mountain.