Yup, you get into the mountains, you need power, no doubt about it, we have a lot of 2 lane on the Trans Canada going through the Rockies, and some of the passing lanes are so short they are a joke, so the better the power in your rig, the easier to get out of the way of people, and to get past the slower trucks. Makes a big differance on the overall trip times, and means more sleep at the end of the trip as well.
Gord.