This is a short video of the truck pulling up and down 6% grades with GCW of 15k lbs. I have decided it has to maintain 65 mph or higher in order to pull these grades in 4th gear. If you drop below that then it will kick down to 3rd gear until you get back over 65 or so.
I'm gonna apologize for the crappy quality here as you can't see the road and the dash at the same time. I'll look to post another one if possible.
