Looking for help/advice on truck ...

[Willy1823]

Alright so I’m learning here and trying to figure this out. I have 3.55 with a 13 spd. I have a demandated ISX, pulling a skateboard. I run all over the country. Most of the time I’m running heavy, but sometimes I’m hauling insulation. What your telling me is keeping the truck around 1600 rpms when I’m heavy, and keep it on the lower side when I’m light? Just wanna make sure I’m understanding this?