MMO in gas - RTS 5W40 - 2003 Deville - 5090 Miles

[ronrackley]

Originally Posted By: ARCOgraphite
Is that SAE 40 too thick for that GM engine even in FLA? At thickest I would run 10w-30 rotella triple protect with 1 qt sub of Formula Shell 5w-30.


I'm thinking about switching to the new Rotella T5 10w30 [or is it 5w30?] HDEO when I use up the remainder of the 5w40 that I have on hand. It's not that I believe the 40 weight to be necessary or even better for my cars. I only went to the 5w40 to get the stout additive package of an HDEO - which I could only find in 5w40 and 15w40 - when they reformulated the 5w30 and 10w30 oils I had been using for years [Mobil 1] to reduce their ZDDP additive level a few years ago. I just wanted to keep the same basic additive package that oils had when my engines were designed "for good measure," I guess you could say, and the HDEOs gave me that. I ran some 5w40 and got good UOAs and on road trips found the gas mileage to be basically the same - maybe a couple of tenths of a mile per gallon less, at most, as explained in other posts I've made here about that - so I've run with it ever since.

Rotella can be bought in jugs at Walmart at decent prices and, since it has been very good to me, I'll probably stick with the brand and not go looking around.

 

[ronrackley]

Originally Posted By: Santo Fontana
Do a few more uoas with NO MMO at all and see if anything pops up.

thanks for the uoas!


I just changed the oil in this car and added 20% MMO this time to double check on something I think I noticed - less consumption with the MMO runs. I left the last oil in for almost 10,000 miles to have an extended drain UOA, although I am basically a 5,000 mile oil changer, and I had to add a quart at about 6,000 miles and it looked to be down at least half a quart on the dipstick at the end. The 5,000 mile runs with MMO seemed to have less of a drop so I'm taking another look at that.

I have never been one to use MMO in the oil except for special purposes, but if the consumption is indeed less in this engine that will be a first for me. I have seen some old leakers get significantly worse with MMO in them to quiet lifters and carbon knocks and such.

 

[Pontual]

So, according to a tribologist in here, he concluded that MMO is red dyed kerosene, right?
Kerosene is Fuel in oil analises, right?
If that's so, why the Fuel% is
Blackstone Magics again or University Labbull?

That I'd like to get that uncovered! I had to ressucitate this one ...

Anybody do know the answer to that? Would won a shaft pin!

 

[btanchors]

ron -

I do not know anything about MMO, so I cannot speak to that. You indicated the UOAs represented intervals in which the MMO was used as a gasoline fuel additive, and not added directly to the oil, correct?

If I am correct, I believe I have a better explanation for the increased TBN on your most recent UOA.

The most recent UOA represents an interval in which your oil was in service from mid-May to early September - the warmest months. The others occurred when the oil was in service during cooler months.

I know you are in Florida, but I'm guessing the recent UOA, during the hot months, resulted in very little warm-up time and little or no condensation in the oil. I think this has a tendency to keep TBN higher, as fewer acids form.

Also - was the mix of highway/city driving the same for all UOA intervals? In general, lots of cold starts, and colder weather in general, lowers TBN. Fewer cold starts, and warm weather tends to keep TBN higher.

My guess is this affected your TBN readings more than the MMO.

 

[Garak]

Originally Posted By: Pontual
Kerosene is Fuel in oil analises, right?

I believe that Blackstone infers fuel dilution through flashpoint, rather than by a more direct means. So, if they know the flashpoint of kerosene, and the dye doesn't lower that flashpoint, MMO won't have any fuel dilution.

 

[Pontual]

Sure. The flash poin of kerosene is between gasoline and Diesel, much less than 350F. Die is negligeable. Definitely would decrease the bulk, wouldn't it? Did it? The difference was only 5F lower 415F is a too high number for when 20% kerosene is added ... Even 400F isn't nearly attainable, with 20% kerosene dilution. That's the Mystery, Garak. Who screw up? Hahahah.

 

[gallydif]

Originally Posted By: ronrackley
Originally Posted By: ARCOgraphite
Is that SAE 40 too thick for that GM engine even in FLA? At thickest I would run 10w-30 rotella triple protect with 1 qt sub of Formula Shell 5w-30.


I'm thinking about switching to the new Rotella T5 10w30 [or is it 5w30?] HDEO when I use up the remainder of the 5w40 that I have on hand. It's not that I believe the 40 weight to be necessary or even better for my cars. I only went to the 5w40 to get the stout additive package of an HDEO - which I could only find in 5w40 and 15w40 - when they reformulated the 5w30 and 10w30 oils I had been using for years [Mobil 1] to reduce their ZDDP additive level a few years ago. I just wanted to keep the same basic additive package that oils had when my engines were designed "for good measure," I guess you could say, and the HDEOs gave me that. I ran some 5w40 and got good UOAs and on road trips found the gas mileage to be basically the same - maybe a couple of tenths of a mile per gallon less, at most, as explained in other posts I've made here about that - so I've run with it ever since.

Rotella can be bought in jugs at Walmart at decent prices and, since it has been very good to me, I'll probably stick with the brand and not go looking around.

40 is fine too for florida. I've mostly ran 10w-40 in the town car even though it calls for 5w-30 and IMO it runs smoother with the 40. Also, I know a taxi company here that uses 20w-50 dino in their crown vics which also call for 5w-30 and some of those have 500k+ on them.

 

[Garak]

Originally Posted By: Pontual
Even 400F isn't nearly attainable, with 20% kerosene dilution. That's the Mystery, Garak. Who screw up? Hahahah.

I have no idea. If the KV is still fine and the MMO worked its way out through volatility, or at least much of it did, I don't know what they'd say. If the flashpoint is good and the KV is good, and that's all they're working from, they really can't claim fuel dilution, given the testing they do.

 

[Clevy]

Originally Posted By: Pontual
Sure. The flash poin of kerosene is between gasoline and Diesel, much less than 350F. Die is negligeable. Definitely would decrease the bulk, wouldn't it? Did it? The difference was only 5F lower 415F is a too high number for when 20% kerosene is added ... Even 400F isn't nearly attainable, with 20% kerosene dilution. That's the Mystery, Garak. Who screw up? Hahahah.


The mmo flashed off Pontual. Come on. Use your noodle.