I used to get between 6-700km a tank hand calculated, I know it's not true but bare with me, my lie oh meter used to say I was gettin 28+mpg now it's saying 8-12mpg, my truck has a air dog 2, afe pro gaurd 7 filter, 4" straight pipe to 7" single stack, 6" lift and 35x12.50x20s but I was still gettin good mileage with all that, and wicked power, my truck lost to my gfs Chevy cruze the other day with my spartan 310 on... I was embarassed that was my first race I've ever lost....