Corrosion X is some REALLY GOOD STUFF!

There is a web-site for it. It is even approved for aircraft use (certain formulas)! I was boating with a Fed-Ex pilot who agrees that the stuff is GREAT! My bro uses it on his twin Suzuki 140 outboards in the Gulf of Mexico. It is that good - even in salt water.

I just use (in normal use) MMO mixed with turbine oil or ATF or some other oil that I deam worthy.

For long term... as mentioned: Fill'er up! It can only help right?