Not liking this.
Quote:
Swell seals 1 1/2 % to 3% and then lubricates them to prevent wear
Then says..
Quote:
Protect rubber seals
The problem is with modern engines and some additives is seal compatibility, there are more different seals materials in use today then ever before.
Long gone are the basic nitrile and neoprene based sealing materials that were common even just a decade ago.
These materials while not compatible would swell without failure, some other materials wont. One example is small engine carb fuel bowl O rings, take it out and sometimes its so swollen you cant get it back in the channel, but it didn't fail and leak.
Some of the modern materials don't act that way, they fail and leak.
Unless you assembled the engine yourself and knew the material of every seal and gasket you could actually cause oil leaks with some additives if run long term like a full OCI.
I am convinced many oil leaks are cause by people being too nice to their cars engine trying to protect it from normal wear with additives.
Spec oil is tested for seal compatibility, stray from that and you just opened a can of worms with possible consequences.
Then there is always the poster that says "i used product X in the oil in my Ford for years and no leaks" yeah okay but i have a Toyota are the seals made of the same material?
IMHO engine oil today is so good you really don't need to add anything "extra" to the oil unless you are attempting to fix a real problem on a neglected engine.
Check these list..
http://www.fluidseals.com.au/o-ring_application_guide.php
http://mykin.com/rubber-chemical-resistance-chart