: can i use marvel mystery oil?

07-28-04, 12:15 AM
i have used marvel mystery oil in the engine and fuel of my other vehicles, and had no adverse problems. can i run it in my 98 sts? i only wonder because it is such a high-tech engine (compared to my other vehicles) and don't want to mess it up.

thanx for the input,


07-28-04, 10:23 AM
I havn't added MMO in years. If you change oil regularly (and use good oil) you shouldn't need any extra additives. It is a great detergent but you've already got that in the oil now.
I'm not sure if it would damage the catalytic convertor. I'd say there is no reason to use it.

07-29-04, 08:22 AM
I use MMO on occasion and find it can help keep the engine from building varnish that can cause lifters or rings to stick.

That being said, if you keep you oil changed at regular intervals with a quality brand, and excercise the engine to keep from building up excess carbon, MMO will not likely be necessary.


07-30-04, 09:35 AM
:coolgleam I think MMO is a pretty harsh solvent. I used another product in my (decrepit old) work van called Auto-RX that's supposed to clean the engine more gently and condition the seals. The result has been a major improvement in engine smoothness. Basically you change your oil and filter, dump in the stuff, drive 1500 miles with it in, change the oil and filter again (just plain oil, no additive), drive 3000 miles, change it again, and you're done.

07-30-04, 10:11 PM
MMO is not a solvent per se. It is high-grade machine oil that can penetrate very fine clearances (such as hydraulic lifters) and will dissolve or work through some varnish buildup. It is not a harsh solvent; it cannot hurt your engine.

As to whether any additive helps much that of course is a debatable issue. I have found MMO to be very useful on occasion, for freeing sticky lifters and rings.

As I said it won't fix broken parts and it is not a miracle cure, but it can free up sticky ones without any damage to your engine or fuel system. It is a tool (chemical) used for the right problem it will work just fine.