DEF
On an average how much DEF are people using per trip(or tank fill up) on late model DP.
Forum Discussion
In a motorhome Cummins estimates a DEF usage rate of 2%. So, for every 100 gallons of fuel you would use 2 gallons of DEF. Assuming 8 mpg fuel mileage, that's 800 miles per tankful or 400 miles per gallon of DEF. At 2.79 per gallon for DEF that's .007 cents per mile.
