Best magnum MPG?

Ok guys, I'm in the middle of putting a 5.9 magnum with a 600 cfm eddy carb in my 72 Duster. Today I filled up my 01 Ram 1500 with a 5.9 and got a whopping 10.7 mpg. Now I know the truck is much heavier, is 4x4 and has more wind resistance but it got me thinking, how much are y'all getting for mpg? If possible, include what car, trans, tire size and gear ratio y'all have and carb or efi. Fire away.