2004.5 Dodge Ram 2500 Cummins, 6 spd manual, 3.73, stock. I am averaging around 18-19 mpg daily driving, unloaded. With 5000-6000 lbs I'm around 15-16 mpg. I haven't pulled heavy, so I'm not sure. I run 4 oz of Howe's Meaner Cleaner in each tank.
My brother's 2001, 2500 Cummins, 5spd will...