Mobil 1 uoa's (high iron)

[TooSlick]

I think the iron is valve train wear and ring/cylinder wear, since these are the main ferrous materials that see high pressures and oil temps....

For example, crankshaft journals are much harder than bearing overlays, so for the most part, it's the bearings that wear and not the iron from the crank

Tooslick

 

[haley10]

quote:

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Originally posted by TooSlick:
I think the iron is valve train wear and ring/cylinder wear, since these are the main ferrous materials that see high pressures and oil temps....

Tooslick

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I'm going to assume that is the case for now. Thanks for all the input.

 

[buster]

quote:

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I'm going to assume that is the case for now. Thanks for all the input.

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Me too. Take the good with the bad. All oils have their strengths and weaknesses as we've seen.

 

[buster]

Notice on the oil study at spacebears that the GF-4 Mobil is showing much less Fe. Most likely due to break-in. However, it' has much less Boron. If Boron does have an impact on Fe, which I DONT believe it does anymore, the new Mobil 1 EP oils will show high Fe as well. Lets see what happens.

 

[1sttruck]

Cutlery is hobby, and I end up sharpening lots of things. I like using a sharpening oil with whatever type of stone I'm using, aluminum oxide, Arkansas, diamond, ceramic, etc., and have tried a number of oils. For awhile I was belnding mineral oil with WD40, but now I just use WD40. With a fine stone (small grit) there is very little abrasion with mineral oil, but I get decent sharpening with WD40 on almost all of the stones as it's a pretty light oil.

Mobil is often described as being 'thin', thinner than other oils of similar grade, so perhaps the higher iron is just a result of the oil being thin. Considering that there are typically more smaller particles than bigger ones, and that they will often increase with mileage, one would expect more wear due to silicon/dirt with the thinner oils. For that reason it seems reasonable to use a thicker oil for extended drains, and to upgrade one's filters when using thinner oils.

 

[buster]

quote:

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"...The oxygen in air dissolved in oil forms metal oxide films which have anti-wear and limited anti-scuff properties. Iron oxides, especially Fe3O4 on steel, is effective in reducing metal to metal contact. This oxide is frequently found as wear fragments in used oil when low wear occurs..."

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...just another little thing to make it more difficult to determine wear via oil analysis. Molekule's theory seems correct.

 

[Winston]

Where did you get that quote?

Also, why would Mobil 1 do this more than other oils? So all things being equal, I do not see why this quote justifies high iron in Mobil 1.

 

[TooSlick]

The implication of all these, "it ain't wear" posts is that Mobil 1 mysteriously allows rusting of non-wearing internal engine surfaces - even in engines that get frequent use.

I say, if it walks like a Duck and quacks like a Duck, there's something fowl going on...

 

[Geoff]

I read on the SHO site how some techs had been quoted as saying that Mobil 1 caused more valvetrain wear than the SHO engines run on conventional oil. This is the typical internet anecdotal stuff that might have some truth to it.

I have been a long time Mobil 1 user, but the pattern doesn't look good having looked at the UOAs on this site for about a year now. I still use it in our boat (11th year and squeaky clean, but oil pressure is dropping low at idle for the first time - but could be another problem like oil frothing).

My conclusion thus far is Mobil 1 has low volatility and leaves no residues over time, can handle extended OCIs, but it is not necessarily the best oil from a wear perspective. However, clean, non-sludged engines may have as much or more impact on longevity as the minor Fe ppm differences.

 

[buster]

Who knows what it is....everyone has their take on it. I'm sure Mobil tests their oil as good as any. Take it for what it is....

Remember though, if one were to base their opinion of RL off $20 UOA's on BITOG, where would RL stand? If the race teams read this site, would they still use it?

 

[TooSlick]

Perhaps straight PAO's don't provide very good corrosion protection in comparison to petroleum basestocks? Or maybe replacing the polyol-ester portion of the basestock with the less expensive AN is to blame, since Delvac 1 is still a PAO/Ester. That actually makes technical sense, since the highly polar esters do bond to metallic substrates.

I say take two high carbon steel plates - coat one with Delvac 1 and one with the GF-4, Mobil 1 and leave them outside for a week. I bet the M1 plate shows significantly more corrosion.

Where's Mr. Bob Winters when you need him?

This is tailor made for a Bob experiment!

 

[oilyriser]

Run some hot used oil slowly through a magnetic trap, and re-test for iron. Mechanical wear particles will be removed from the oil, while most iron oxides will not. But maybe the non-magnetic particles are worn off anti-wear films and not corrosion from moisture. It's rather complicated.
Or #2 maybe the metallic wear particles are large, and partially trapped by the filter, and don't show up in the UOA as well as particles shed by anti-wear films.

[ July 22, 2005, 08:54 PM: Message edited by: oilyriser ]

 

[Rob Taggs]

I have always been suspicious about Mobil and the high iron bit. Its sort of like politics. You can give the evidence up front and folks that are for a certain individual will never believe the truth no matter if you have pictures, papers, and all other proof.

 

[buster]

Here is the source: http://www.herguth.com/technical/PHYSICAL.HTM

Tooslick, pretty good assumption. AN's replacing Esters is not an unreasonable assumption IMO.

Their seems to be two schools of thought with Mobil 1: (generally speaking)

1.) Being it is factory fill in many high end cars and is Mobil's flagship product, it's then a great oil. Excellent reputation in NASCAR. Under this scenario you would think that Mobil does extensive field/lab testing when working with top engine builders.

2)It's simply marketing. A good oil but could be better and the name carries the weight.

 

[427Z06]

Here's my conjecture for the day.

Dino oils depend mainly on low viscosity basestocks and the shearing of the VII to achieve their "fuel economy improvement" (read low friction) under normal driving conditions. Relatively low viscosity index synthetics with minimal shearing need another mechanism to reduce friction and achieve a fuel economy improvement. "A classic example is oleic acid reacting with iron oxide to form a film of the iron oleate soap. The low shear strength of the soap film causes the low friction."

Given the above, one would expect to see lower Fe levels in UOAs with non friction modified oils and vice versa. Examples, Delvac 1, GC, other HDEOs will generally have lower levels of Fe than synthetics that meet fuel economy improvement criteria, all else being equal.

 

[Gary Allan]

Let's see .... I think that we now need to differentiate "wear" and "para-wear" ..or "pseudo-wear". Now first ..we acknowledge that there is no difference between "wear-wear" and "sympathetic-incidental-co-wear".......

..but it makes us feel better about it.


It was kinda like at my old job. If you didn't CYA ..someone, as though it was an obligation, shoved something in there. "Hey, your lucky it was one of us that did that to you!! Some stranger could have done that ..and how would that feel? We care!"

 

[427Z06]

Gary, let's call this Politically Incorrect wear. Maybe we can get Bill Maher to host a few threads?

Well, running some rough numbers with the normal caveats, if you removed a 40 atom layer of Fe off the cylinder walls of a 350 CID V8 you would end up with 11 ppm of Fe in 5 Litres of oil.

40 atom layer of Fe ~= .0000004"

 

[LarryL]

Maybe we could get four balls and rub them together. Whoever has the smallest scars on their balls has the least amount of wear. I don't think anyone is going to equate wear to an iron particle count in a uoa, with out a microscope and some more testing.

 

[TooSlick]

I think the consistently high iron is due to rust/corrosion that occurs even when the engine isn't being used. I also think this is why the Mobil 1, EP is overtreated with boron.

You'll note that Amsoil is also using high levels of borates esters in their new 0w-40/10w-30/10w-40, Four Stroke Marine lubricants. These are intended for applications where fuel/moisture contamination and rust/corrosion during off season storage is a major issue.

My take is that PAO based synthetics are generally lacking in corrosion protection and special corrosion inhibitors like boron are highly necessary in these formulations....The Amsoil, GC and Delvac formulations may also have enough ester content to minimize this type of wear. I just don't know....

Tooslick
Dixie Synthetics

 

[427Z06]

Well..I guess we're down to two theories. TooSlick's rust/corrosion only, my combination of friction modification with possibly some corrosion. Take your pick until we otherwise see some credible evidence.