4x4ord wrote:
^^^ Shiner, if on average you are towing up a 1% grade with wind and at 65 mph you would be getting more like 6.5 or 7 mpg. At that kind of power output I would expect the transmission of a factory tuned truck to select 5th gear.
Well it doesn't. It will try and hold 6th using a lot of boost and fuel to do so. My brothers stock truck is the same way. So was hos 2012 PSD and my father in laws 2019 PSD. Hence the reason why the manufacturers give us the select shift option which they even state in their owners manuals that it is best used when towing heavy(per the gear ratio ratings) or on steep grades. A 13k trailer is 76% of what my truck is rated tow with 3.42 gears.
