I almost saw a fight in a hotel parking lot when a Duramax owner claimed to get 23 mpg .... My goodness are diesel owners sensitive to that subject :D

Obviously not a diesel, but my gas job Ram is like Mark is describing, rather strange in fact ... Towing my Capri and open trailer, mostly highway's but almost regardless, it will be right around 15 mpg (14.5-15.2) when I go something like 3 hours. Drive the truck empty, on the highway, and it will pull 22-24 mpg ... Drive the thing normal, around town, off the highway and it gets 17. Damn near what it gets towing.