Anyone that has torn down an engine that used STP consistently knows the stuff has a thick film that sticks to everything. I think one big advantage for using it is reducing dry start wear on a car that sits for extended periods between start ups.
back yrs ago , old timers used it in their old oil burners that were worn out . its nothing but an ultra hi viscosity additive . I used to have an uncle that blended oils for dx sunray , he knew a but load about oils and additives.
