Have you figured a highway mpg with your setup, Jon?
No. It isn't easy to say because the variables that affect gas mileage can either have a slight effect or a dramatic effect. With the AD truck you have to take what you get. Wind, hills, running the A/C, driving over 60, tire pressure, windows down or windows open all impact mpg. Even running the wrong spark plug will make a difference. This coming fall I'm going to get serious about that question and account for all miles driven, all conditions and come up with an honest overall average. I could tell you driving from Texarkana to Dallas (flat as a pancake in a zone where the wind will normally be at your back and on a day when no A/C is needed and driving 55) it is possible to get between 17 and 20 mpg, but driving from Dallas to Abilene will be a different story.
