MPG went up??
Usually you hear about people's MPG going down, well mine went up this week. Last week I got the "Speed limited in 50 miles. Exhaust system fault." DEF had about 500 miles left in the tank. Drove a few miles and the error message went away. When I filled up a day or so later I reset the mileage and noticed better fuel economy. Figured it would go away, but I'm almost on empty and at 14MPG. Was getting about 12.5. Same driving habits (85% city unloaded). Oddly this tank hasn't seen the highway at all. Been 100% city driving and still 14mpg. Previously I saw 16 highway and 12.5 city. I used to see about 14 city and 18-19 highway when I first got my truck, but that went away about the same time I went with off road tires. I figured the drop in MPG was the tires, but I'm not so sure now. I'm also noticing far less regens. Only 2 this tank. Before the error message it seemed like I was constantly in regen (causing the bad MPG I assume).
Anyone else experience this or can offer any wisdom? Worth taking in to see if there are any updates/re-flashes needed?