CM 871 getting 3.6 MPG

[Chamberpains]

Make sure all tire pressures on the whole unit are up to snuff. With that weight your hauling id have every last one of them at the tires rated psi limit. That what I run on my truck with absolutely no ill effects. And i run FAK at all load ranges.

Check the air filters

How are your driving habits. Are you like 90% of drivers?. Hammering through the gears because you think its a race not a business? This one murders most drivers MPG. Slow down. 60 mph average sounds like your pushing it hard to keep it up there. Ease up and work with the terrain more and not against it. Average speed shouldn't matter very much to someone chasing MPG.