A couple of things come to mind, the enclosed trailer's profile (aerodynamic, wind drag at the rear of the trailer), head wind at the time of your trip from Fresno to Turlock (nice 80 miles drive) and there is just a slight elevation (~200') difference, If you take the same route often, I would watch if your HL is consistently running at higher RPM and down in the 5th gear on that same section/same direction of the road (if opposite in direction and running in a higher gear, there may just be on a slight long stretch of incline).
P.S. If you were using cruise control, it could have downshifted to maintain your set speed. With load, it does sometimes make the AT a bit more agile in balancing between speed and the appropriate gear to use.
P.S. If you were using cruise control, it could have downshifted to maintain your set speed. With load, it does sometimes make the AT a bit more agile in balancing between speed and the appropriate gear to use.
