> What is a wetting Agent? Just a compound to reduce the surface tension of
> water. As long as it doesn't congeal due to the heat and clog the radiator
> then it's probably a good thing.

I would add.... surfactants reduce water surface tension, thus making it
easier for it to squeeze into places...

like head gaskets close to developing a leak anyway?????
or marginal coolant hoses????

Perhaps it has the added benefit of helping to locate leaks or potential
leaks?

I believe my mechanic (list recommended) uses it in his vanagon.

Bill