Viscosity and Wear

[buster]

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I don't see any evidence in the used oil analysis section to support this contention. If I've missed a used oil analysis that will back this up please post the link. I realize that good back-to-back comparisons of one viscosity to another are scarce as hen's teeth but I've found a couple of good ones between Mobil 1 0w-40 and Mobil 1 Xw-30 that show that the 30-weight protected as well as or better than the 40-weight.

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I don't buy into the idea that thicker is better. It depends on many things like the engine, type of driving and oil. I'd say it's most likely a range between a high 20wt to low 40wt that would do best in most engines. Some cars like the BMW need a hevier 60wt oil but for the most part, they will do fine on the range I just mentioned. I don't have any proof of this so it's just my guesstimate. And as Patman states alot, Vette engines could maybe even benefit more from a heavier 30wt oil such as Amsoil or Redline.

[ July 16, 2003, 06:12 PM: Message edited by: buster ]

 

[Cary]

Just a couple of more thoughts on my previous post.

It is my understanding that over the past 20 years the operating tempurature of cars and their oil has gone up from 180-190F to 210-220F. Given the increase in tempurature, you would think that manufactures would have gone to a 40 weight oil since they are the same thickness at approximately 210F as 30 weight is at 185F.

I also have to wonder how a 10 year old formula of cheap mineral oil would look on the Mobil graph. I suspect that better base stocks and additive packages have made current mineral oils much more stable over a wider tempurature range than they used to be. Perhaps the current mineral oils have signifcantly closed the gap between mineral and Synthetic compared to the past.

Just my thoughts. I'm not an engineer and I don't claim to know hydrodynamics.

Cary

 

[yannis]

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Originally posted by moribundman:

. Citroen=Peugeot (in cahoots with Nissan , IIRC), Ford is losing a lot of business in the EU. BMW owns Rover (and Morris?). Is Leyland still buliding cars?
What about Lada? Are those still just Fiat cars built under license? What about Russian cars? Moskvitch, anyone? There's just no way to talk about all of them.

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Nissan is cahoots with French Renault, BMW sold Rover to independent investors at least two years ago because they were losing big money (British couldn't believe that Germans had bought them ,went nuts and stopped buying German Rovers-overestimated sterling didn't help the exports) and finally Russian Lada's are using GM motors and new-ugly bodys.

 

[Cary]

[/QUOTE]Nissan is cahoots with French Renault, BMW sold Rover to independent investors at least two years ago because they were losing big money (British couldn't believe that Germans had bought them ,went nuts and stopped buying German Rovers-overestimated sterling didn't help the exports)

[/QB][/QUOTE]

Renault owns a large chunk of Nissan, no secret. BMW split up Rover and sold the Land Rover division to Ford, and practically had to give the rest of the Rover division away. BMW got rid of Rover because they couldn't get the quality up to par and they had invested billions in the process of trying to. Brits didn't stop buying Rovers because they were owned by BMW, they stopped buying them because they were crap. Rover was in financial trouble when BMW bought them.

Cary

 

[Jay]

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Originally posted by Ray Garlington:
Jay wrote

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As far as the Maxima spreadsheet data is concerned, I don't think it's useful because you're not comparing apples to apples. If you look at the individual used oil analysis you'll find a wide range of exceptions (like 30-weight user "A" uses a K&N air filter, user "B" had a coolant leak, etc.) that make the data useless for the type of comparison shown.

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Jay,
There are half a million miles of used oil analysis represented there. A few problem children 'average out'. This kind of data is much better than one or 2 examples. Someone should start assembling 'our' used oil analysis into a database of some sort.

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I disagree. The only meaningful comparison of one viscosity against another is in the same car, same driver, approximately same conditions and the car has to be in good mechanical condition. The problem with the spreadsheet data is that all the individual samples are "problem children". The sigma is too great to make your average meaningful.

 

[moribundman]

quote:

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Nissan is cahoots with French Renault, BMW sold Rover to independent investors at least two years ago because they were losing big money (British couldn't believe that Germans had bought them ,went nuts and stopped buying German Rovers-overestimated sterling didn't help the exports) and finally Russian Lada's are using GM motors and new-ugly bodys.

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Nissan is also working together with MB (farm vehicles). Are you sure Renault doesn't own Citroen by now?

Lada, espcially their little offroader, used to be fairly popular in (East and West Germany at a time when SUV's really didn't exist. I saw plenty Lada Niva there. My neighbor had one.

 

[Mark in NY]

3 things -

1 - This has been a particularly interesting and enjoyable thread.

2- I may have missed the point on the Europe reference. I thought you-all were wondering what they do in general over there as far as oil quality and viscosity usage goes.

3- Cary, we seem to think very much alike in analyzing this topic. Your last reference to operating temp years ago vs today and the similar running viscosity was almost an identical thought that I posted on the Contour boards some time back.
I suggested that rather than getting all tied up relating cP to SAE grades, you could just think of it as moving the engine thermostat down 30 deg F when you go from SAE 30 to 40. Thats what has happened over the years as themostats went from 160-180-192-197.
I went to the trouble for that post to look up some clearances on Ford Mustang engines between 1966 and today. It really has not changed.
This indicated to me that the tiny CAFE effect is the driving force behind the move to lighter oils.

 

[tweeker43]

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Originally posted by Mark in NY:
tweaker43-

how many samples, and cars of Mobil drive clean oil were there in this database?

From this sample of data, this Mobil conventional oil will allow cars to last 2 million miles.!

Of course there are many questions that beg to be asked- one is - do the guys who beat on their cars the most, the same guys who tend to spend more and tend to use the "best" oil?
I drive like a little old man and use 99 cent Acme cheapo oil. My wear numbers are better than my friend who uses 9 dollar synthetic because he races his car weekly.
More data leads to more questions, and so it goes.
It is indeed tough to pick the magic oil that will extend our engine life.

If only I devoted as much detail to my internal UOA - you know, HDL, LDL, but thats another board !

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the second number is the miles on that brand of oil, and the fourth number is the average miles per change. you can get the number of samples by dividing the total miles by the average.

in regards to the validity of the data, i would imagine that any person who does oil analysis would have some kind of bias

 

[YZF150]

I have thoroughly enjoyed the civil, respectful conclusion to this exchange. Thanks, members, for taking the time to present your points while honoring the diversity of opinion of others.

 

[tweeker43]

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Originally posted by Ray Garlington:
wow, the last 2 posts by Mark in NY & Tweaker43 are awesome.

question for Mark

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Realize that this is a logrithmic scale but somehow the resistance of using a -40 in place of a -30 because of the arguements over high temp visc differences escapes me.

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Sorry, couldn't keep up with you here. Could you explain your point a little more?

question for Tweaker43
For each oil grade did you add the respective ppms and mileages for each oil weight that was reported?

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sorry that formatting was brutal. i'm batting 1.000 on posting data that looks like crap.

i took the spreadsheet from the maxima site and put all the UOA data on one sheet. i then tallied all the data for ppm for each entry. after that i could sort for brand or oil weight. some entries weren't counted, like moly, because they could be from the oil, wear or engine coolant.

 

[Ray Garlington]

Tweaker43,

It appears that on average, the Maxima likes the heavier grade oils better than the thinner grade oils.

Can you identify which of the oils on the spreadsheet are synthetics to see if synthetic only results would be different? Also, how old are the maximas that are represented here (any particular year)?

 

[MolaKule]

"Last thoughts from engine teardowns & rebuilds- boundry lubrication (moly etc)does not apply to bearings. If the oil presssure is lost under power(like the sweeping turn at Lime Rock) the bearings melt and go away in the blink of an eye."

I beg to differ, because this is what boundary lubrication is for. Preventing or reducing friction reduces local heating of the bearing surface, whether the surface is a sleeve bearing, needle bearing, or piston ring sliding on a cylinder wall. Every little bit helps.

 

[QuadDriver]

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From mark in NY:

I do not see thousanths difference between old engines with good and poor oil maintenance. The difference I see is ten-thousanths. It is really a difference of metal surface quality (as the term is used in machine shops)- the scuff resistance the oil provides- that I see. 2 cylinders that mic up about the same can show visual differences that I attribute to oil protection. Take two motors with 125K miles, one a clanky oil burner, the other a fairly tight quiet running unit. The differences in specs will be measured in 10ths(thousands) not thousands of an inch. This is why "Million mile motor still in spec" ads are worhtless as a claim.

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EXACTLY! I bow down at your feet.

 

[MolaKule]

And "still-in-spec" represents an acceptable range of clearance tolerances; it could be the engine's bore is on the low side of "in-spec" or on the high side of "in-spec," but still within the acceptable range of "spec." So what does this prove? Manufactures have a range of deviations for engine in-spec and out-of-spec.

 

[Mark in NY]

MolaKule,

I agree with you on this when it concerns (steel to steel) ring to cylinder contact, cam to lifter etc. I have seen moly refered to as a sub-surface lubricant in some circles. Yes, under EP conditions it does all the good stuff- prevents galling etc.
I just dont see this happening down-under in the land of soft lead bearings. The lead does not touch steel under normal operating conditions. I think "EP" contact rules just do not apply to something as soft as the typical bearing alloy.
This relates directly to the decades old corporate debate between Mobil (and many others) vs Amsoil concerning the validity of the 4-ball test for testing automotive engine oil.

Teardowns of many blown racing engines taught me that putting gobs of very expensive moly powder in an engine did nothing extra if you momentarily lost the all-important oil film.
Getting a suficient oil film between moving parts **and maintaining it at all times** by the proper combination of pump output pressure, oil viscosity, oil pathway modification, addition of Accusump type auxilary oil supplies, etc, makes your motor last and last....
This is why I continue to harp on viscosity here. It is the one variable that is easily adjusted on our street cars that can make a difference in engine life.
Although I will admit that the above concerns more extreme conditions that only apply in a limited way to lower power/long term engine endurance. Generally the only oil related engine failures I observe on street cars these days are due to loss of oil supply due to oil sludge.
So while I wave the flag about 0-40, or 10-40 being a good thing vs 5-30, the more important real-world concern is to buy an oil that from experience has a good reputation for maintaining a clean engine. - Mobil drive clean, Pennzoil, other conventional oils mentioned on this site, any Real synthetic.

 

[Jay]

So let's see...from the Maxima spreadsheet data a Nissan Maxima driver (or a smattered Toyota driver) who chooses RedLine oil can expect to see 2.42 times more wear than if he had used Mobil DC blend over the same interval. Pity the poor Amsoil Series 2000 oil user who can expect to see 5.7 times more wear in his Maxima than if he had used MDC blend over the same interval.

Obviously, these averages are useless for comparison purposes and the viscosity data is just as useless for all the same reasons. There are too many variables involved in each individual sample.

 

[Terry]

Great discussion on BL and lead in bearings etc. Mark is sharp and knows his stuff, I like doing analysis for people like him ! He sure reminds me of a valued customer in NYC area.

I agree that if the bearings are grossly mashed you'll see a failure fast. What Molakule is bringing out and what I have seen as a Racer and tribologist is the thin hydrolube layer being distorted by bearing deformation in the most minute levels affecting longer term issues, thats where the soluble moly and other barrier lubes shine ! Another consideration from my point of view is what is the source of lead? Which bearing? What are the mettalurgical structures and what other alloys are incorporated in that signature. If you as a builder give me an accurate picture of the composition of the engine I can give you near real time feedback of how to continue to make HP and keep it up for a 3 hour endurance run around Lime Rock !


The mixed and barrier lube regimes are still poorly understood by ALL involved in the study of same.


BTW I agree with JAYs last statement on variability in automotive engine oil analysis and the spreadsheet UNLESS you can data point nearly every or most of the variables and account for that. Which can be done and why field trials testing is so expensive and time consuming.

[ July 17, 2003, 11:53 AM: Message edited by: Terry ]

 

[Ray Garlington]

Jay says

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...(he) who chooses RedLine oil can expect to see 2.42 times more wear than if he had used Mobil DC blend over the same interval. Pity the poor Amsoil Series 2000 oil user who can expect to see 5.7 times more wear in his Maxima than if he had used MDC blend over the same interval.

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Jay,
You have pointed out (one of) the errors inherent in using a single sample. In the portion of the spreadsheet to which you refer, the drive clean data was from a single voa (~3000 miles), as was the Amsoil 2000 data (~10000 miles). The redline data was 4 samples. That is not enough sample data to warrant comparison. When you aggregate a sufficient amount of data, you start to get valid results.

If you want to see how amsoil works, take a look at the line that includes samples totaling apx 300000 miles. Looks pretty good to me.

 

[Last_Z]

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Originally posted by QuadDriver:

quote:

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Originally posted by moribundman:
nortones2,
The speed limit had been lifted in Montana some time back in the mid/late '90s. The speed limit has been 75mph for cars and 65mph for trucks in Montana since '99. That's because people went hogwild, and because those highways were not suitable for higher speed.

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The autobahn (which simply means motorway, not high speed proving track) now has a 130kph speed limit for its entire length, and due to safety emissions concerns, is 100kph in populated areas - welcome to the 2000's. (I did nothing more scientific than ask a friend in beverstadt) just because you DONT get pulled over is not a replacement for speed limits (btw deer dont exist in germany? when did *that* happen?) I have routinely driven 100mph between RR pass south of vegas to the laughlin cut on the sam kinnison highway (save searchlight) and dont get stopped. Signs say 65.

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Quad....I'm affraid I'm gonna have to disagree with you. As Moribundman stated, the autobahn IS in fact unlimited in many places. I have been driving in Germany for over 4 months now and this is what I've seen: Upon entering a city/town/village the posted speed limt on the autobahn is 130Km/H (which is almost 80MPH); also the speed will be limited to 130/100/80/60 Km/H on dangerous strecthes of roads (ie: steep declines, curves and less than perfect road conditions among others). Besides that, the Autobahn is unlimited with the requirement that the driver uses his/her common sense. Max speed is recommended BUT not limited to 130Km/H on the open road.
I'm currently in Kaiserslauter, Germany and usually drive my rental minivan at speeds in excess of 200 clicks (power limited).
Rick

EDIT: BTW, France also has the same rules as Germany (give or take) and England is somewhat the same.

One more EDIT: Yes, there are deers here in Deutchland....I almost killed on the other day. Also, I have a German approved American license, which means I took the German test, which means I know what I stated is correct.....why? Because I'm a Transporter (WHOOAA!!) in the military and we constantly get updated info and training.

[ July 17, 2003, 02:35 PM: Message edited by: Last_Z ]

 

[buster]

I'm going to try taking a sample of Mobil 1 10w30, followed by 0w-20, 0w-40 and maybe D1 all at 6k miles and see what the differences are. This should be a good comparison of various visc. under the same conditions, same engine and same formulas.