Will MMO+5w50 kill or clean the engine.

[GR_CoB]

Got some Castrol 5w50 in my stash. And some MMO, always got it. The vehicle I wanna brew this in originally calls for 5w30 or 0w30 per owners manual. During oil change 4 quarts fill up the filter and show right between the Full and Add marks on the dipstick. I was thinking of running 3 quarts or 5w50 and a quart of MMO for an OCI of 5k miles or more. Then once MMO burns off, if it does, and level get's to "add" mark - I'll just top it off with a quart of 5w50 again and then top off as necessary. The reason why I want to do this type of slow flush is because the car was in Fleet usage for most of it's life and was pretty neglected. Will MMO bring the 5w50 closer to 0w30 somewhat?

 

[crazyoildude]

i use mmo oil the time i dont know what it would do weight wise but it cleans pretty good

 

[kschachn]

Gee I thought you had about 100 quarts of 0w40 Pennzoil Ultra to run through.

 

[JC1]

I doubt it would kill the engine. I would try 3.5 quarts oil and .5 quarts of MMO for your first run. How dirty is this engine?

 

[Shannow]

Given that MMO is a "subtractive" (ooposite of additive, it dilutes additives and thins), I wouldn't go too hard substituting it for real oil.

 

[GR_CoB]

Originally Posted By: kschachn
Gee I thought you had about 100 quarts of 0w40 Pennzoil Ultra to run through.


I do. But got 5 quarts of this castrol 5w50 and thought of burning through it on the next OCI before the car goes on a steady diet of 0w40 SRT stuff. Next oci is still 5k/3months away, but I just wanted to see if my idea is beneficial or suicidal, based on oil gurus from this wonderful website aka BITOG.

 

[GR_CoB]

Originally Posted By: Shannow
Given that MMO is a "subtractive" (ooposite of additive, it dilutes additives and thins), I wouldn't go too hard substituting it for real oil.


I might need some confirmation on this, but isn't 5w50 castrol is loaded with additives? Don't remember where I heard it. So maybe a 25%/75% mix will still keep the additives in acceptable level while providing the cleaning abilities of MMO?

 

[GR_CoB]

Originally Posted By: JC1
I doubt it would kill the engine. I would try 3.5 quarts oil and .5 quarts of MMO for your first run. How dirty is this engine?


The fill hole has a baffle, so can't see through it. But I'm planning on a Valve cover gasket replacement soon, so will take some pics. But whenever I just got it - there was some varnish on the oil cap and the baffle. And the driveworks filter that was on there looked alarming a bit when I cut it open.

 

[Nick1994]

Skip the MMO and just use 1 quart of the 5w50 to blend in with regular oil per oil change.

 

[turtlevette]

Put the mystery oil in 500 mi before you dump. Put a quart of kerosene or diesel 10 minutes before you dump.

 

[901Memphis]

Mix it with PYB 5w20 instead, skip the mmo

 

[Kuato]

IMO

for most additives. Since you're planning to use a 40 wieght, then perhaps a 1/2 and 1/2 mix of the 5w30 and the 5w50 would get you closer to that mark. Maybe one extra quart of 5w50 to balance out the additives.

 

[Rolla07]

Just do some short oci's, no need for mmo

 

[kr_bitog]

Originally Posted By: SanProsan
Got some Castrol 5w50 in my stash. And some MMO, always got it. The vehicle I wanna brew this in originally calls for 5w30 or 0w30 per owners manual. During oil change 4 quarts fill up the filter and show right between the Full and Add marks on the dipstick. I was thinking of running 3 quarts or 5w50 and a quart of MMO for an OCI of 5k miles or more. Then once MMO burns off, if it does, and level get's to "add" mark - I'll just top it off with a quart of 5w50 again and then top off as necessary. The reason why I want to do this type of slow flush is because the car was in Fleet usage for most of it's life and was pretty neglected. Will MMO bring the 5w50 closer to 0w30 somewhat?

I think it is a good idea if you want strong dose of MMO, it will thin out nicely. However, I may not run it for too long (perhaps 1k)

 

[Donald]

Why would you buy 5W50 for your stash regardless of price?

Use the proper weight oil and forget the MMO. Unless you pull a valve cover and find it sludged up, you do not even know if it needs cleaning or just regular oil changes.

 

[Panzerman]

ALOT of people aginst adding MMO, never uses MMO. I hate those kind of comments. I wouldn't be afraid of running your combo, I would just shorten it to 3,000 mile oil change. I've used MMO with 5w30 and it didn't seem to thin the oil, but it was a 7 qt slump. It doesn't burn off and you should be impressed with the smoothness it brings. MMO is really good stuff. If you use it, you ll like it.

 

[DoubleWasp]

I have had good success with MMO, but again, be sure to make sure you even have a problem before trying to address one.

 

[panthermike]

It certainly won't kill your engine, but others have suggested, I would go with 1/2qt MMO or just mix with thinner oil.

 

[GR_CoB]

Thanks for the feedback everyone! I was looking for feedback specifically from those who have used MMO. I see a lot of proof from people who have used it that it does work wonders. And then there is a camp of those who never used it, but believe that it's no good, without any proof. I guess I'll go with my gut feeling and believe those who have used it And I got 5w50 for $2/quart at Autozone, that's why I have it in my stash. I didn't specifically went out of my way just to get 5w50. Original plan was to brew it with 5w20 or just for top offs to strenghten up the add pack. Any more inputs from those who HAVE used it - would be appreciated. But all inputs are welcome, it is BITOG afterall.

 

[Doog]

I have used it but actually got better results from Pennzoil Platinum or Redline. PP seems to clean the best in neglected engines but it is very slow and gradual.