Anybody here ever used Redex upper cylinder lubricant additive in their fuel? A buddy of mine who own a BMW 540i E34 swears by the stuff to reduce his fuel consumption. He says I should try it in my Prius. I'm nervous about adding things to my fuel, especially in a car as advanced as the Prius.
i like seafoam for old cars, it really helps to clean pcv system, and throttle body, but i wouldnt use it on a prius, i think prius engine will go for like 900k miles before any crazy maintenance