I'll be curious of the effects on the DEF usage after the recalls. My 2016 eco diesel would get almost 8,000 miles before I had to fill (2.5 gallons). My 2020 eco diesel gets about 3,000 miles before I fill (2.5 gallons). My driving is the same about 90% highway (150 mile commute daily) and the models are the same (Laramie, crew cab, 6.'4" bed, air suspension and all the factory goodies I could add to the model). One difference would be the gear ratio as I have the 3.21 in the 2020 and I believe the 2016 was closer to 3.56 (forget exactly what) but I did not get the towing ratios in either. Just to be clear I fill with 2.5 gallon jugs when the gauge hit 1/2 tank. at the same time I reset the mile gauge to record the miles I get. I fill both at the 1/2 tank mark, it keeps DEF in the tank so I do not have an issue and the 2.5 gallons put it close to the full mark. I assume the higher usage in the newer generation of engine was to help on the emission issues the older generations had.