Marvel Mystery Oil, Good - Bad?

I've heard good things in the past about using Marvel Mystery Oil, like it will improve your engines life and performance over long term use of adding a quart to every oil change. It also says on the bottle to add about 4 ounces to every 10 gallons of fuel. Is this worth it? This is my first tacoma and is about to roll over to 90k and I was gonna do my first oil change on it, I plan on switching to Mobil 1 synthetic, the original owner used conventional oil. but should I also add a quart of MMO? Or is there any other additive anybody recommends?

 

I wouldn't add anything to the engine oil...

The design of modern motor oil is more then good enough of itself.

I have used MMO for other things tho'

It's great to put a few drops into the piston cylinders
of a motor that will not be run for awhile.

I used to use that in my RC car/plane engines...
if I knew I would not be operating them for a period.

^ lubricates and minimizes wear during start up
after extended periods of being idle.

other then that... I've no use for it.

 

You're already switching to synthetic oil so I wouldn't bother with the Mystery Oil. Give it a seafoam treatment, clean your MAF, replace your filters and plugs and call it a day. Modern synthetic oils are pretty good stuff.

 

Marvel mystery oil.... theres a name I havent heard in a min..
If your using synthetic, dont use it.
Good stuff though.

 

This.

We use it for the air impacts at work.

 

I've used it in the gas of a motorcycle that hadn't been run in a while. Seemed to do the trick.

 

forget the Mobil 1...stuff is crap IMO

I use only Motul 5W40.

Total Full Synth is a good cheaper substitute & use higher oct(91) w/ a higher mileage motor like mine (213K)

 

Just curious, but why do you use higher octane fuel in a higher mileage engine?

 

this and this. . . i use it for everything at work