i only have 500 miles on the truck so far, so cant really comment. my only trip so far was north along the front range to WY. I was supposed to go to Crested Butte next week and was looking forward to see how it did on the passes, but to much work is getting in the way now and had to cancel--damnit. BUT, i can tell you it did great on the hill on the way to WY, passed cars with ease etc. its not I70 climbs, but im guessing it will be great. stay tuned