Stan Wilder wrote:

Never put any additives in your oil that contain teflon, or miracle
cures.

In aircoled motors the teflon reaches the ideal temperature to cling and
build up under the piston rings, in effect you are building a layer of
plastic up under your rings. It causes pre-mature wearout on the rings.
BEEN THERE DONE THAT !
If your warer cooled engine ever gets really hot you get the same
results.

I'm inclined to avoid any additives other than Marvel Mystery Oil and
it's only good once or twice a year to clean your crank case while you're
driving. The trick to Marvel Mystery Oil is... it saturates carbon and
aids in burning it off of valves and piston tops.