I was wondering too. Presently I'm getting in city 11-12 mpg that's with an enclosed trailer attached and when I hit the highway on the weekend(empty) trips,I get up too 24+mpg.
well after fueling it after the 4th time. i'm getting 12.1 on 3rd and 4th tank 12.9? and thats mixed driving like a granpa.
highway/city' is it normal for a diesel, my '94 5.7tbi (in top notch shape) i get 10-11 mixed.