[AutoTchr]

Originally posted by lee
Couple of assumptions: 1) oil doesn't have much affect above the top ring, 2) "pure" gasoline is a better solvent than lubricant, and 3) gasoline contains unstable components that lead to deposit formation in high temperature areas in the induction system such as injector nozzles or valve stems - mostly from the 'heavier" components since the lighter ones evaporate away when the engine is stopped.

So why additives?

Lead used to be the prime lubricant in fuel. But those days are long gone. Not sure how long various "detergents" have been used. So what lubricates the valves, AND keeps the deposits from clogging injectors and sticky rings? Only thing left is the additive package.

I'm not a chemical/automotive engineer - don't know what's in those additives - but it's gotta be tough to balance detergents with lubrication - normally mortal enemies.

So, IMHO, buying the cheapest stuff with a bad detergent package only risks need for the occasional fuel system cleaner. Buying the cheapest without a good lube additive risks valve recession in the head - who remembers aluminum heads without hardened or steel valve seats when lead was phased out?

Lee, You may have had different experiences, but I have never fixed a car with fuel injector cleaner. Any fuel injection work that I have done has involved replacement. Maybe becuase I am always concerned about comebacks and cleaner (if it works) is temporary at the least. Now in support of your comments, I think that you may have a point about the additives. But be careful, it can be as much of a marketing ploy as anything else. Slightly O/T but I have a friend that does some advertising for a guy that makes custom putters. This guy says that the more he charges for his putters, the more he sells.........