Passing and being passed by 18 wheelers has another aspect many do not know.
Many, if not most, 18 wheelers have their engines governed, due to insurance requirements, or as a way to save fuel (according to management - that debate is for another topic). I think most privately owned truck do what they want, but they are not the only ones out there.
So, when heavily loaded Truck starts to pass you, using the speed momentum he has built up, and you both start up a hill, his speed will bleed off quickly, while our coaches can maintain speed or accelerate, usually. As a result, the poor trucker is stuck out in the left lane, line of traffic behind, embarrassed as heck and discussing the RV drivers lineage and intelligence.
If you see a trucker trying to get around, and he does not quite have enough pep to do so, turn off the cruise and help the guy out a little. You may be more help by accelerating ahead of him, if he generally drives slower than you.
Anyway, he may be at a power disadvantage, and will really appreciate a help getting out of that left lane.
If you use CB you might let him know what you are trying to do, and he can let you know how to best help him.
We really are in this together.