I track my mileage on each fillup (by hand) and have the following data:
Stock mpg: 24.11
+ Firestone A/T: 20.6
+ MAF unplugged (disables EGR): 22.69
+OME light duty lift: 21.09
+Large Thule cargo box, fully loaded for 3 people for a week, 2 mtn bikes, cooler, etc: 18.6
This is over 65,000...