The brew is 8oz MMO = Marvel Mystery Oil and 16oz PS = Power Service Diesel

 

(also new and trying to get a grip on understanding diesel better than what the army teaches me)

and this is added to every tank when you fill up? is it better to wait for an almost empty tank? or just add it every time? add it when it starts sounding different?

 

I add it to each fillup of about 30 gal. every once in a while I'll skip a tank (not having it in the truck).