GuamMini wrote:
I put in the Gunk Lead Additive and the car runs perfect, just a few minor tweaks.
The trouble is, Jim, that these products won't (or shouldn't;) really have any immediate observable effect on how your car runs.... in 10thousand miles or so though, when things start to get a bit lumpy, you find you'll be out of pocket big time to repair the damage that has snuck up on you.
In a quick look I couldn't find anything technical on the Gunk product. But its a big company and been in business a long time so maybe they know something. Your problem is making sure that the product you buy is the one you need for
your engine..ie something that is specifically intended to protect valve seats.... Most of the comments I see about Gunk and valve noise etc centres around cleaning hydraulic lifters (which you don't have).
As has been said, lead has 2 basic functions in fuel; octane support and valve seat protection. Some materials (like toluene) will raise octane ratings ..and so may be considered a "lead substitute" but won't protect the seat...
If you see inclusions such as sodium or potassium mentioned in the product blurb then there's an indication that the manufacturer is looking to protect valve seats...
Cheers, Ian