Completely understand where your going here. I think any and all of us are right to question the data and how it’s produced. Especially when we are spending our hard earned money based on it. Please don’t take the way I worded my response to discount the products entirely. They will continue to refine the calibrations, and I think as a whole make some huge efficiency gains to the modern emissions systems. In the mean time I think it’s important for us to ask questions as they come up to understand where the data came from and how it’s being used.
All im saying is that if you get 1000 miles per gallon of DEF, and you're getting 20 mpg then your getting 50 gallons of diesel to 1 gallon of DEF.
If you're getting 23 MPG, and presumably an increase in efficiency produces a decrease in DEF consumption based on the statements made thus far, then you would burn 43 gallons of diesel. which would if linear equate to about .9 gallons of DEF over the same distance. so if you drive 15K a year, you will save 1.5 gallons of DEF a year maximum.
Now, lets say this tuning kit costs the absurdly low price of 500$ and a gallon of DEF costs about 3$. It would take you 160 gallons of DEF to equate to the cost of the tune, which at 1.5 gallons per year given 15K a year, would take you like 100 years to break even.
Im not ragging on there tunes, im just saying that that data is misleading at best. HP numbers, ok, torque numbers ok, MPG numbers ok, but trying to tell me that this tune will save me money on DEF is absurd.