This post is not about diesels, but I'll just add that if you do lots of driving in hills and over mountain passes, absolutely nothing beats a diesel and today's excellent exhaust brake systems.
Couple of years ago, I headed west over Wolf Creek Pass in SW CO, towing a travel trailer with my GMC Sierra Duramax. Using my cruise control, and with the Tow/Haul mode and exhaust brake activated, I was able to make it all the way from the summit of the pass westward to the bottom without ever once touching the brakes. This system really works well.
