Now ive been pondering getting a smarty myself, which setting would be considered the mpg setting or is it just having the box that gives better mpg

 

It depends on what you have and how your truck is set up! You have to play with it! After my 90hp sticks I still haven't found the sweet spot! Takes alot of tanks of fuel and good records to see what works and what doesn't! With stock injectors #5 was best for me! 24mpg record!!

 

ok thanks all i have is a straight pipe and a k&n replacement filter also have the silencer ring taken off but that doesnt change anything

 

smarty and dr. performance