I have been tossing aroung the idea of running a quart of this in my Merc 502efi. The motor is a late 90's and has about 600hrs on it (I use mercury 20w50 full synthetic oil) and still runs good but uses a decent mount of oil. Does anyone have any experience with this product in marine applications? I searched on here and didn't find much info. I also read a lot of feedback on automotive applications and there seem to be mixed reviews. Any input would be appreciated. Thanks guys.

I run it in my 2004 Supercharged Silverado, But I run 10w30. I don't know how much it will benefit since your using fairly heavy oil to begin with. I did notice the oil turns Blacker/Quicker. I don't notice it being any quieter or anything, I'm just going on the personal satisfaction that when I'm screamin it at 6500rpm it has a lil more protection than just the oil.

I run 15 40 & lucas.

I run 30wt and lucas, just added it this oil change, more protection is a plus in my book.

They make a synthetic version too. I run it in everything.

Had a buddy that does carpet steam cleaning have motor issues. We found pieces of ring in the pan. Added (2) quarts during that oil change and the motor ran until his new truck arrived 4 week later. That sold me.