More fuel mileage?s

All I can offer is progressive shifting. Watch your tach and shift low as possible without lugging.

You may hear something bout tires and roll resistance, but I can't help with that.

I hear that the Lucas fuel additive helps mpg, but again, I can't attest either way...

 

To be honest mid 6s mpg on that year truck is very good. Not saying you cant get more out of it. About the only way you can squeeze a little bit more would be adding more aerodynamic closing the trailer gap. Maybe shifting differently. I have a freightliner cascadia 2011 and the most i can get out of it is 7 but it hangs around mid 6s.

 

My 2000 classic xl would get about that. Usually 6-6.75 on occasion I can break 7 if lots of empty miles. Reefer also 80k a lot. Detroit power also 11r24.5 however 3.90 and 18 double over. Also no idling. Speed 60-70 mostly

 

Low to mid 6s is what I would expect. Which isn't bad. Don't let the lunch counter supertruckers fool you this new crap isn't getting appreciably better. Slightly better, (like 1/10ths ) but not like 1-2mpg more. That is just BS.

 

Tarp the cowhides for better air flow over the trailer.

 

as far as I know your not doing too bad, can it get better? maybe.
most of the guys that do super great fuel mileage are very light a huge percentage of their loads, doesn't mean there isn't a guy hauling 80k and still gets 8+, mpg but I'm skeptical.

just a quick anecdote, I have a friend that is always maxed out (70,000 lbs dump truck), it's got low gears (4.10) 13 double over 1000 + hp on a 15.8, he goes to another part of our state to work for a few months, always racing and you can hear on the phone how he runs that truck, I'm always telling him to slow down.

well to end the story he's average is better than mine by .5 mpg while I'm doing everything the way the mpg freaks preach, I drove like that for a few months and really didn't notice any advantage and I don't like driving my engine like that, non of these engines were design to be lugged, my theory is drive at or over 1500 rpm which is where these engines power really takes off and don't make unnecessary stops, plan your trips and you'll be fine.

It takes a lot of fuel to move 80,000 lbs at 55 or 60 mph.

by the way my average is at 8 mpg but a lot of 45 mph and stop and go, when I go to those other places where there's long stretches at 60 and 65 mph, my mileage suffers and looks a lot more realistic than when I work locally which is 99% of my work (locally is 200 mile round trip).