I have experimented with different brands of diesel and determined that my truck, 2019 stock RAM 2500 Laramie 4x4, likes Walmart diesel best. When I fill up at Walmart, I average 23+ MPG and can go 600+ miles on 29 gallons. When I fill up anywheres else, my MPG drops to under 22 and struggle to get 550 miles on the same 29 gallons. I do have a 31 gallon tank but only take it down to 29. One other thing I noticed, the DEF fluid last longer and the miles between full Regens is over 1200. I have a daily commute of 75 miles one way, about 40 thru 40 - 55 mph zones and 35 on the interstate at 70+.