Well my Jeep did great on the east coast coming over the Smokies, but over the Rockies it is getting hot. I was watching transmission temp and not seeing any issues. The coolant temp was the problem. The engine could have easily pulled my trailer over the passes at 65 mph, but the coolant temp would start creeping up. I backed off when it hit 237 degrees. After that I turned off the AC and kept the rpm's in the 2000-2500 range and let the Jeep pick the speed. For the steepest parts I was doing 35 mph and coolant temp was fine. Most of the passes I could do between 40-50 mph without getting hot. I'm disappointed that the Jeep could do 65 mph no problem if the coolant system could handle it.