2017 GMC/Chevy DEF tank!

otrfun wrote:

Me Again wrote:

Cummins12V98 wrote:
My consumption of DEF was 48.6g in 23,416mi @ 481.8mpg. That is with about 10k of that being towing 33K combined.

I may have used 10 or less 2.5 gal boxes in 24.5k. That would be around 1000 mpg. Chris

I've typically seen DEF usage expressed as a percentage of the amount of diesel consumed. Expressing it this way takes into account how much fuel is used. Fuel and DEF usage is dependent on load, driving style, etc.

Have 12k on our '16 Ram 3500. 7k of that was towing a 12k 5th wheel while averaging 11 MPG (diesel). Typically get 17 MPG (diesel usage) when not towing.

Since the truck was new, we've used 8.5 gallons of DEF and burned approx. 930 gallons of diesel (or an overall average of 12.9 MPG of diesel usage). That puts our DEF consumption at .9 percent of diesel consumed. Or, if you prefer, a gallon of DEF used every 1,411 miles (1411 MPG of DEF).

If I assumed Cummins12V98's average diesel consumption was 14 MPG for 23,416 miles, his DEF usage would be 2.9 percent of 1,672 gallons of diesel consumed. Assuming the same 14 MPG for Me Again, his DEF usage would be 1.4 percent.

Ram says DEF usage is dependent on load, driving style, etc. It's my understanding that typical DEF usage (for a Ram Cummins) is supposed to be 1 - 2 percent.

Ron, tows really heavy!! He would be considered worst case scenario. His wife is a bit like Lucy who collected rocks along the road.