Yes, mostly, I pretty much use this truck for trips, I can look at the fuel guage and the milage and tell what is going on. Last summer I had the fuel system cleaned and they reflashed at the same time. I made several trips pulling a 4 horse slant and got 13, a couple of months later I made the same trip empty and got the same, 13. I went back to the dealer and another reflash and back to 17 to 19 depending on how I drove. These trips are over I70 from Denver to Page AZ. I also have a 30' Montana and when everything is running right I can get 10 to 12 when in my lame mode I get 6 to 9. When I started resetting my codes, even though they don't show up it doesn't make a difference right away but after a couple of hundred miles I can actually feel the truck respond. The truck goes from sluggish to very responsive, you know exactly when it happens