I own a 3.5L Ecoboost and pull a TT with a loaded weight of 3000 poundss
. We just got back from a 6000 mile trip throughout the eastern part of the US and we had no problems. I agree that the mountains in the east are mot anything like the west, but, the truck handled everything without breaking a sweat. I kept track of the tranny temp, never above 210 degrees, and the engine temp never moved. This was in 954 degree heat with the A/C running constantly. The gentleman that I bought the truck from bought a 2018 that was set up exactly like the one he sold me. I thin that says a lot about the truck.