1982 GMC 4 door dually, how much

What is the MPG on these big ass thangs

mine gets 8mpg towing or empty never changes

I have an 89 crewcab dually. She gets about 10mpg with the factory tbi. Thats unloaded.

i have a 2000 chevy crew cab with a 454 in it and not towing i get about 16mpg and towiing i get about 10-12 thats with a 18 ft dove tail and my s-10 on it.....