ok so i have a 2001 s10 ex cab 4.3 auto. i believe it is a cpi if im not mistaken. well i just bought the truck 2 weeks ago. i am getting 15 mpg (using the ol' filler up and divide method.) i should be getting near the 17 mpg gallon range shouldnt i? i just put some stp fuel treatment intoday, hopefully so it can clean my injectors and what not. what can i do to get more mpg, i have also just replaced the air filter, the truck has 48,500 miles on it. carfax report sais it was registered in pennsylvania, i was told that i mite need to get the air to fuel ratio reset or something, i dono. im kind of engine stupid but i am always willing to learn and would rather do something my self, rather than taking to a shop.