1st DEF fill up
Filled the DEF for the 1st time today. Took 4.2 gallons. Mileage was 5400. According to the calculator, that equates to just under 1300 miles per gallon. Dash info center said I had 470 miles left on ...
Forum Discussion
Just towed 16000# LQ horse trailer 1000 miles, took 3 gallons of DEF to top off, DEF was full beginning of trip. 2011 GMC ext. cab 4x4 duramax/Allison. Truck averaged 9.3 mpg, kept speed at 67 mph and below. That's around 107 gallons of fuel, DEF usage within what GM says is normal....... I guess.
