Newbie Pics w/questions

[Field Scout]

My first 2 tanks of gas I got about 17 to 17.5 mpg with 06 adv auto with wilderness roof rack, then turned t-bars and added highlift + pull pall to the roof and added winch now on a great day get 16 but 15.5 on average not sure if it was changing the profile of the truck(take a tilted brick and set it straight making it less aerodynamic) or all the extra weight and increased roof drag with the extra gear. probably a little of both since I had the roof basket off a short time for roof plastic replacement and seemed to go a little further on a tank of gas. btw, nice truck