Originally Posted by redwngr
DEF usage is a ratio to fuel usage.
Use more fuel, it will use more def
Should be somewhere close to 1.5 gallons on DEF per 100 gallons of fuel.
Don't mean to doubt this but are you sure that is how its metered? I put in one of those blue DEF boxes and it seemed to be gone in two tankfuls at my towing consumption (8.5 MPG)
2005 Long Bed, Crew Cab, 3500 Dually
PPE tune, AFE Intake, SS Highflow exhaust
Uprated Allison Trans, Kennedy Air springs
55 Gallon fuel tank, Gooseneck Trailer hitch