over 20 is BS in my book.
Chev Duramax 1 ton 4x4 12' flatbed, got 12.3 loaded, from a honest guy.
First you say "over 20 is BS in my book" then you throw in the "from a honest guy" comment right after that.....so if thats not inferring anybody who claims over 20MPG is dishonest, then accept my appologies for reading too much into what you wrote.
Go to any of the diesel websites, and you'll see plenty of people who claim to get over 20MPG highway from their Cummins diesel trucks..so there must be a lot of people out there who have nothing better than to BS about it...or maybe people do get that, and you are wrong. If i remember correctly, are you not from Alaska? I'd imagine with the extreme weather conditions and bigger grades you encounter out there than i do in the east (Pa, Del, NJ, Md, Va) that it might be harder to obtain the mileage i get. Just because you dont experience something, it does not make those that do all BS'ers.
As far as driving rigs...my father was an owner-operator for over 25 years, and i drove and helped maintain his trucks, so I know a little about commercial driving too.