When I first got my 1009, Everything was changed, like Westech stated. This past fall, I noticed the milage going down from mid 20's to the mid teens. After further inspection was done, I discovered that the rear brakes were dragging and the E-brake as well.(seems my son pushed it down and it never fully released properly) I had to replace the both rear cables and pads and cleaned everything thoroughly(lots of rust and sand). Only thing I forgot to do was the front brakes at the time. As soon as it warms up again, the front end will be gone over and replacements made accordingly.
I'm not a person with a lead foot either. My truck seems to like 50 to 55 mph best. Believe me I can tell, if I have to go on a fire call and get back in the truck to go home...my eyes bug out a bit. These trucks were not built to win a NASCAR race, and they were probably rarly if ever driven faster than 35 mph on post/base. Mine is not a daily driver as well.
I believe Westech has the right idea, keep up on the maintenance, keeping a clean fuel filter and ait filter are key part to the picture. As for something special in the fuel, I use Lucas every other fill up, I also don't go below 1/2 tank especially at $3.59 p/g I do however average mid 20"s, I'd love to see 30.......maybe one day with a tail wind. haha
