Drive Clean 7500

[1911]

Hey Guys,

I was kind of thinking that Drive Clean 7500 synthetic blend may represent a good value in the $2.50 to $3 price range with some group 4 PAO in it. Do we know whether or not the conventional portion is group 2 or group 3 or a mix of conventional types? IF it's group 3, then thisd oil may be a steal........at least compared to group 3 Syntec. I plan on running 5w30 in the Texas summer and 5W-20 in the winter for my 2.0 Mazda 4 even though the manual specs out the 5W-20. I'm one of those guys who is not comfortable with running the 20wt in 100F summer weather with high engine temps. I did read one technical article where they said that even if you have enough viscosity present to build an elastohydrodynamic film, debris particles larger than the film thickness will cause some wear and micro-scoring. We all know the film thickness goes up with viscosity.

 

[Starbreaker666]

Acording to all the previous posts it's III/IV. It's deffinatly going into my new '04 Monte Carlo SCSS as soon as I finish this last 3k mile break-in run on 5w30 Valv AC. And I am even going to use the GM OLM

[ March 25, 2005, 09:43 PM: Message edited by: Starbreaker666 ]

 

[Ugly3]

1911 - We all know the film thickness goes up with viscosity.

Do we now?

 

[1911]

quote:

---

Originally posted by Ugly3:
1911 - We all know the film thickness goes up with viscosity.

Do we now?

---

Ugly3,

I'll put it to you in these terms........ anybody who does not know this fact knows absolutely nothing about hydrodynamic or elastohydrodynamic lubrication. The film thickness (assuming you have one) is dependent on several factors. I'll name a few briefly here using hydroplaning in your car as a good example of hydrodynamic lubrication in action.
1) Speed!!! the higher the speed, the higher the film thickness.....does your car hydroplane when going fast or slow? For low speed applications, we need to raise the lubricant viscosity to get effective lubrication. Any plant engineer knows this well.
2) lubricant viscosity.....the higher the viscosity, the thicker the film. Assuming lube is present, if the viscosity is not high enough there will be no highly protective film and boundary type lubrication will prevail where there is some metal to metal contact at asperities. Water is a lubricant but it's viscosity is low....I believe it's about 1 centistoke. In low load high speed applications, it can be a great lubricant (it will corrode ferrous metals of course). If you run your car over oil puddles instead of water puddles, you would find that it "oil-planes" (lifts off the ground) at much lower MPH speeds than on water simply because of the viscosity effect.......most folks mistakenly think this is because oil has some kind of special slipperiness. If you heated a thin oil enough to get the viscosity down to 1 centistoke, your car would not know the difference between the water and the oil.
3) Load (in pressure)!!! The higher the pressure (combination of load and bearing size), the lower the film thickness!!!

I will stress now that in film thickness calculations, the thickness is much less sensitive to pressure than to speed and viscosity. IF you would like some generic film thickness equations, do ask and I'll break out the dusty books.

With all this said, it should be clear now that any talk of ideal lubricant viscosities (we hear it too much here) for an IC engine is simply ridiculous. Such talk only makes sense in terms of "the best compromise". Look at the differnet friction surfaces in an IC engine (main bearings, rod bearings, thrust bearings, cam bearings, cam lobes, tappets, roller chain, piston ring area, valve guides, etc). Each one of these places would ideally have it's own lubricant viscosity (of course this varies with speed and load too!!!!) based on the factors I mentioned above. Specifically, the cams would love to have 50wt oil or much higher in all cars. This is why they are made of hardened materials, cause there is a boundary lube condition here with metal to metal contact and the friction modifiers become important. It a lot easier to lube a steam turbine because the load is simply the weight of the rotor (does not change), and the speed is a constant 3600 RPM. The car engine is a complex mess. We need to think of auto lube viscosities as a best compromise!!!!

1911

 

[JohnBrowning]

1911. I agree 100%!!! This is why I am so partial to 5W40's either synthetic or semi-syntetic! I think they are the ideal comprimise for about 90% of the population in the USA!

 

[TallPaul]

1911 Excellent post!

 

[Terry]

In mixed and boundary layer phases there is no lube present for brief and intermittant cycles so in a sense I disagree with 1911's text book based statement. I do agree that with traditional engineering thought that compromises will be made.
Thats why in a racing engine with serious boundary and mixed layers issues I choose "appropriatly" low vis lubes and make up the difference with non hydrodynamic solutions,1911.

Your position is logical but too theoretical in practical application. I'll take a well made molacule that is relatively low vis to a thicker one that is barely physically or chemically stable but cumbersomely viscous.

I am in agreement that the Mobil blend may be a good oil but have not seen enough of it in analysis yet. All we know for sure is that it is a "blend" and that it contains 18% more cleaning "agents" than the MCC5000. I suspect it is mostly grp II and III, possibly GrpI at some unknown level.

Our helpful Mobil factory contact is missing in action.

 

[JohnBrowning]

quote:

---

Your position is logical but too theoretical in practical application. I'll take a well made molacule that is relatively low vis to a thicker one that is barely physically or chemically stable but cumbersomely viscous.

---

Outrage,Scadal,Mass Pandimonium(sp)!!!!!!!!! 5W40's around the world are shocked and scared by Mr. Terry Dysons (profesional tribologist) scandalis remarks!!! The ACLU will be representing the coalition of 5W40 oils!!

Terry keep that up and you might wake up with gallon of 25W70 on your pillow!

 

[TooSlick]

1911,

Do you have a question, or are you simply stating some basic principles of tribology 101?

Seriously though, I believe the Mobil 7500 series oils are GP II/GP III (or possibly PAO/GP-II), with what I suspect is a fairly low TBN (7-9) additive package.

I'd just run the 12 TBN Mobil 1, 5w30, Extended Performance, and use a significantly longer drain interval.

Tooslick

 

[Blue99]

Well, per Carpy's post, the Clean 7500 is a Grp III and PAO blend.

We have every reason to believe that ExxonMobil now has a source of low cost GRP III, whether it is a 120-125 VI base oil from the Raffinate Conversion process in Baytown, or an XOM facility in the Asian Pacific.

Low cost GRP III has made an impact in the marketplace, an example being the Motorcraft brand of oils produced by ConocoPhillips with 70% of the base oil being the imported GRP III from SK oils.

 

[1911]

quote:

---

Originally posted by TooSlick:
1911,

Do you have a question, or are you simply stating some basic principles of tribology 101?

Seriously though, I believe the Mobil 7500 series oils are GP II/GP III (or possibly PAO/GP-II), with what I suspect is a fairly low TBN (7-9) additive package.

I'd just run the 12 TBN Mobil 1, 5w30, Extended Performance, and use a significantly longer drain interval.

Tooslick

---

TooSlick,

No disrespect here but I don't get your point. If you go back to my original post, you will see this "Do we know whether or not the conventional portion is group 2 or group 3 or a mix of conventional types?" and I believe this constitutes a question. Also, iF we have to ask questions in subsequent thread posts (not the initial post) then where is the question in your post?

Also, the diatribe was not really on tribology but on lubrication, they are separate topics and experts on one (I'm not in this class but know surely know enough to clarify Ugly3's point) may not be experts on the other as they are separate topics. For example, a lubrication engineer working with the lube system design of a steam turbine may know little about tribology........his job is to ensure that there is a a good enough lubricant film or wedge that he doesn't need to call on the tribologist!!!! But I guess you can think of the fields as two big circles with a little area of common overlap. Speaking of oil wedges, I used to work with one gas turbine that was so ****ed big that the oil wedge moved the journal 0.006 inches to the side (the wedge pushes the journal to the side as well as upwards off of the bearing surface). The cold (non-running)radially oriented (blade tips) clearances were thus 12 mils different higher on on the left side versus the right side sides.

1911

 

[1911]

quote:

---

Originally posted by Terry:
In mixed and boundary layer phases there is no lube present for brief and intermittant cycles so in a sense I disagree with 1911's text book based statement. I do agree that with traditional engineering thought that compromises will be made.
Thats why in a racing engine with serious boundary and mixed layers issues I choose "appropriatly" low vis lubes and make up the difference with non hydrodynamic solutions,1911.

Your position is logical but too theoretical in practical application. I'll take a well made molacule that is relatively low vis to a thicker one that is barely physically or chemically stable but cumbersomely viscous.

I am in agreement that the Mobil blend may be a good oil but have not seen enough of it in analysis yet. All we know for sure is that it is a "blend" and that it contains 18% more cleaning "agents" than the MCC5000. I suspect it is mostly grp II and III, possibly GrpI at some unknown level.

Our helpful Mobil factory contact is missing in action.

---

Terry,

I didn't use/need a textbook to make the simple statements I did. I was just stating some very rudimentary facts about how viscosity affects the tendency towards thick film lubrication. I also don't think any of the text books use the car analogy or at least I have not seen it yet. Lubrication was a one or two day topic in a MECH E class 15 years ago.

Now to the thin/no film race engine application you discuss, are these confined to the valvetrain only? My understanding is that babbitted beqarings are not really designed for any metal to metal contact. They are extremely soft and will melt easily. I suspect even race teams who want to run as thin a lubricant as possible are still relying on thick film (no steel to babbitt contact) lubrication at babbitted main and con-rod bearings. Nobody is running water mixed with Prolong. Thick film lubrication is still the ticket.

 

[G-MAN]

quote:

---

Originally posted by Blue99:
We have every reason to believe that ExxonMobil now has a source of low cost GRP III, whether it is a 120-125 VI base oil from the Raffinate Conversion process in Baytown, or an XOM facility in the Asian Pacific.

---

It's not in the Asian Pacific. It's in Fawley, England.

 

[Jay]

quote:

---

Originally posted by 1911:
... Thick film lubrication is still the ticket.

---

Have you proven that in your Mazda 4? If so, please post your UOA results that show this. I trust you've done carefully controlled tests that back up your theories.

 

[Blue99]

quote:

---

Originally posted by G-Man II:

quote:

---

Originally posted by Blue99:
We have every reason to believe that ExxonMobil now has a source of low cost GRP III, whether it is a 120-125 VI base oil from the Raffinate Conversion process in Baytown, or an XOM facility in the Asian Pacific.

---

It's not in the Asian Pacific. It's in Fawley, England.

---

G-Man -

As I have stated before, I have trouble with the idea of a Fawley produced Visom base oil, with a VI index of 140, being blended into a Mobil Clean formulation that sells for $2 bucks or less a quart.

ExxonMobil converted the fuels hydro-cracker for S-Oils that allows this Korean company to make the GRP III lube basestocks imported & sold by ConocoPhillips.

The ExxonMobil refining technology & equipment branch clearly states, At This Webpage , that this new raffinate conversion & dewaxing process has a capability of 125+ VI.

Eight of these conversions have been installed world-wide. Another is scheduled to go online in Malayasia in 2007.

IMHO, one of these units is supplying the 120-125 VI base oils used in the new Mobil GRP III formulations, not the slack wax feed unit at Fawley.

 

[Jay]

1911, it's not the theories that bother me; it's the way you attempt to use them to bolster your purely subjective or completely unsubstantiated feelings.

As an example:

I'm one of those guys who is not comfortable with running the 20wt in 100F summer weather with high engine temps. I did read one technical article where they said that even if you have enough viscosity present to build an elastohydrodynamic film, debris particles larger than the film thickness will cause some wear and micro-scoring. We all know the film thickness goes up with viscosity.

The board is chock full of members who "feel" that 20-weight isn't enough viscosity for hot weather. They, like you, post endless theories for why it isn't enough. The theories are a dime-a-dozen. Much rarer is someone who has actually done the testing. Now if you had something to back this "feeling" besides theory--that would be something.

Another example:

Specifically, the cams would love to have 50wt oil or much higher in all cars.

Really? That statement is completely at odds with all the expensive testing that Honda R&D did (SAE paper 1999-01-3468). It's also completely at odds with my own testing. In fact, there's a mountain of used oil analysis that contradict this "fact" of yours.

And finally:

Thick film lubrication is still the ticket.

The ticket to what, exactly? Not the winners circle. The racers that are winning are using 30-wt, 20-wt, and thinner--in all almost all forms of motor racing.

 

[Mamala Bay]

quote:

---

The ticket to what, exactly? Not the winners circle. The racers that are winning are using 30-wt, 20-wt, and thinner--in all almost all forms of motor racing.

---

Thinner oil will give better performance especially in this application. A tear down of the motor after each race shows that it cannot be run on an everyday situation.

Race driving and everyday driving is a different situation.

 

[Eddie]

Honda was using Mobil 1 5w30 in their 16,000 rpm Formula one racing engine based on their lab/dyno testing in ~ 1999, ed

 

[Terry]

1911, to answer your query, the theories and thought I am sharing affects all the lubricated areas of a engine.

No one , including me is arguing engineering or accepted physics theory, because thats not my business. Nor do I have an interest in using my time to prove something I already do on a proprietary basis for hire. There are plenty of well read and educated folks here that can argue neat theories all day, and not make a dime....or save an engine or put the customer in the winners circle !

What I am saying , using your example of the fluid flow dynamics of a air foil, is that things change in application, especially in automotive engines. Much like the Dyson Theory
of laminar flow vs. turbulent flow in lubes that
are synthetic ( engineered molacules) and relatively thin compared to the viscosities most accept and are familiar with.

What happens when that fluid film is disturbed and in a turbulent flow mode ? Like air flow over a wing in stall the physics change and if captured can be extremely helpful to the tribologist.

I disagree that tribologists and lube engineering is not one in the same in automotive applications, especially racing applications. The crossover in working a problem with chemists,engineers,physicists,engine builders, formulators, and the poor humble lube analyst is truly amazing. Molakule is a good example of that kind of tribologist. He does not rely on conventional thought to develop,and formulate cutting edge lubricants. Ask Too Slick about the crossover in racing engines to NASA engineering issues on a theoretical vs practical application level.

Films are sure important but which film ? The hostlube hydrodynamic film, the chemical, polymer, film ? Maybe a mixture of both, or what about relying on the coatings films that were applied to the actual moving parts or embedded in the alloys during assembly or manufacture ?

Point is , it is not as cut and dried as your "we all know " statement to Ugly3 came across.

1911, check out a article published and presented at the STLE 58th annual meeting by Tung and Gao on " A study in Break-in film development with different piston ring coatings and correlation with electrical contact resistance measurements". Find the article in LE magazine Vol 59 No.9 9/2003.

25w-70 is a bit heavy for the pillow, John !!! Better than a horse head though.

 

[1911]

quote:

---

Originally posted by Jay:
1911, it's not the theories that bother me; it's the way you attempt to use them to bolster your purely subjective or completely unsubstantiated feelings.

As an example:

I'm one of those guys who is not comfortable with running the 20wt in 100F summer weather with high engine temps. I did read one technical article where they said that even if you have enough viscosity present to build an elastohydrodynamic film, debris particles larger than the film thickness will cause some wear and micro-scoring. We all know the film thickness goes up with viscosity.

The board is chock full of members who "feel" that 20-weight isn't enough viscosity for hot weather. They, like you, post endless theories for why it isn't enough. The theories are a dime-a-dozen. Much rarer is someone who has actually done the testing. Now if you had something to back this "feeling" besides theory--that would be something.

Another example:

Specifically, the cams would love to have 50wt oil or much higher in all cars.

Really? That statement is completely at odds with all the expensive testing that Honda R&D did (SAE paper 1999-01-3468). It's also completely at odds with my own testing. In fact, there's a mountain of used oil analysis that contradict this "fact" of yours.

And finally:

Thick film lubrication is still the ticket.

The ticket to what, exactly? Not the winners circle. The racers that are winning are using 30-wt, 20-wt, and thinner--in all almost all forms of motor racing.

---

Jay,

You clearly are confusing what I used as an engineering term with what you thought was slang for "high viscosity oil". Thick film lubrication is an engineering term referring to having an stable oil wedge present which keeps the metallic surfaces separated (even the high asperities). If a thinner oil can do this, than it is still "thick film" lubication. With this statement I made makes no reference or inference to proper oil viscosity debates. I said it to tell Terry that IC engines are designed with thick film lubrication in mind for the main and con-rods. In other words, we don't use a hyper thin fluid simply as a carrier for surface friction modifier compounds and then hope they keep the motor from seizing. Yes, with the proper definition in mind, I think you're smart enough to realize that thick film lubrication is the ticklet or we'd all be using 0 wt straight with tons of surface modifying EP/AW type additives.

You are reading ideas and things into my writing that I did not even have. My basic description of hydrodynamic theory was in response to Ugly3's comment concerning film thickness versus viscosity. It had nothing to do with "me using some theory to justify some other opinion I had" as you said.

Now where did I imply that 20wt oils were totally nuts to run or a bad design choice? I'm running the stuff right now. However, as should be obvious based on common sense, the high temp film thicknesses will go down at the main bearing and con-rod bearings (relative to using thicker oils) and there is thus a lower factor of safety as far as approaching a point where the film can rupture or fail if temps go a little higher than expected. There is also most clearly a increased propensity toward bearing scoring as the film thickness drops since particles larger than the film thickness tend to score the bearings. Now good filters minimize this for sure. Now Jay, do I need to get references to show this or is that intuitive from making a common sense mental picture of the situation. It's just a plain old fact that we all need to accept simply because it is true. Do you want me to E-mail you a sketch of two metal surfaces separated by liquid with a particle in between them that's bigger than the film? Guess what, the particle will score and/or embed itself in the soft bearing. Now there were some papers going around recently about the benefits of filtering out smaller particles than common filters can trap for this very reason (maybe the Amsoil guys can point to these as they make good filters. They score or embed in the bearings.

Jay, I don't make opinions and then try to justify them with theories, I try to learn some of the engineering truths and then use them to make better opinions.

On the camshaft stuff, you're again missing the idea. The additive packages in the oil are making up for the missing thick film lubrication. Ideally, most machinery is (steam, gas turbines, electric motor bearings) designed to rely on thick film lubrication and as such not all oils are not loaded up with AW/friction modifiers like motor oils are. Turbine oils have almost none. If you did not have the AW additives, you would be better served with a 100 wt oil for this sliding type of contact .....if you could pump it there quickly!!!! Did you consider that the used oil analysis you refer to are also taking into account start-up wear (that's probably 90% of it). None of that contradicts anything I said about hydrodynamic lubrication mate despite your allegations. A higher vicosity lube at the cams will reduce the propensity towards wear an dplace less demand on the AW additives while runnning but may add to it during start-up. If you could use a viscous enough lubricant here, you could actually make these out of softer materials and not rely on surface hardening.

Also, using used oil analysis to fine tune oil choice preferences is not very bright for 30 or so reasons which others here have already made known in addition to lubricant suppliers/researchers themselves. That is not what they should or were intended to be used for. Anybody here with a background in science and statistics should know better. Many on this board do.