Not to start a flame war, because I know that the subject of oil and additives can engender some strong opinions, but I'm new around here and a thread search didn't seem to answer this question.

I'm wondering if anyone out there uses any additives to their motor oil? I started using Marvel Mystery Oil on my first car, a root beer brown 1964 Corvair convertible with 4-on-the-floor. When it ran, it ran well lol!

Well ever since, I've always used the stuff, regardless of what the manual said to use or not to use. I even put it in the gas tank.

The beast I just purchased is a 1995 Montero LS with 177,800 miles. I put some SeaFoam in it and it indeed seemed to quiet down those lifters noticeably. I'm running it like that for another few miles then I'll do a complete oil change. I'm figuring on adding some Marvel Mystery Oil and lowering the oil's viscosity to a 5W-30 weight, as it's now running 20W-50 for some reason.

So, am I alone in loving these additives or am I just plain insane?

 

I just use straight up Mobil 1 10w40 High Mileage.

Either that or: Rotella T, AmsOil, or Redline.

 

I run straight 5W-30 most of the year.
A few months of the year when the desert gets "hot" I run 10W-30.
I've never added anything else to any to my vehicles, not to say it's a bad idea or anything, I just have never needed to.
MM calls for 5W-30 (recommended), or 10W-30 for the Gen III.

 

10w-30 synthetic.. dont care what brand. on my 02 monty (not sport) with 70,000 miles