What is your DEF use rate in miles?

[Wiredawg]

Friends,

Since the end of Mar 2018 when I purchased my new 2017 5500, I've logged about 10,000 miles. I maintain a fuel and maintenance log, but failed to add a column to track DEF usage. Doing a WAG, I believe I'm using about 2.5 gallons approximately every 1,000 miles, so about a gallon every 400 miles. 95% of my miles are towing my 20.2KLb 5th wheel. I'm starting to track now, but thought it would be good to hear from y'all how much you're using.

Thanks, Ron

 

[Learjet]

I recorded it once on a long trip out west to be 550 miles on a gallon of DEF all towing a high profile 12,000 lbs 5'ver. Average for me mixed driving seems to be about 1000 MPG/DEF.

This was measured by topping it off with Pump DEF, resetting my Trip B mileage, running it down until the low DEF light came on and Topping it off again at the pump....I did this Two times...then the fun was over

 

[Sarge]

Wow, those are two way different results!

 

[Dasmoeturhead]

I've never been that curious about DEF usage, because its such a non issue to me. If im not towing and just running errands I can go a couple of months easy. Towing I use about 3 -4 Gallons evef 3,000 MI or so. This is not a hand calculated figure just a ballpark idea. The gauge is completely wrong. It takes 2.5 gallons when it reads 3/4 full, and 3.5 gallons or so when it reads 1/4 tank full. That's why I like truck stop def dispensors, so I can top it off.

My DEF consumption seems to be close to Learjets figures.

 

[Cummins12V98]

Less than 400mpg on a 1,400 mile WestCoast trip all towing at 35k combined.