'97 F250 Powerstroke, manual
We get 18mpg empty, and about 13 with a trailer. It doesn't seem to matter if we're pulling our little 16' Hart with a couple of horses, or a 26' stock trailer stuffed full of cows. Both are GN. (We've never pulled an aluminum trailer, so i don't know the difference)
'79 GMC 3500 (no idea what engine is in this thing, but it's gas), manual tranny
It gets around 9-11, empty, loaded or towing. :wink:
'74 F250 (390), automatic
Old Blue gets about 12 mpg empty. 10, loaded or towing.