oil for a 1997 Boxster

[JoeFromPA]

Originally Posted by JFP in PA

Oh really? We have been collecting UoA's on M96 (and other) engines for many years now, our database entries for the M96 number in the thousands. We have seen Mobil 1's vaunted 0W-40 show lower viscosities than straight 20W oil after only 2,000 miles in an M96, we have seen TBN values that were less than 20% of their virgin numbers in the same number of miles, and have seen more crap in the used oil than one might imagine (fuel dilution, coolant, high metals, etc.).

"Furthermore, boxer engines are typically very easy on oil by their design." You have got to be kidding me.............The M96 is one of the worst oil killers Porsche ever released (and I have been building, repairing and racing them for over 35 years), they run way too hot, have a myriad of minute oil passages that become easily plugged, the chain tensioners are very sensitive to oil’s film strength, they have a lifter and galley design that is forever causing lifter issues, they tend to run bearings dry in hard corners, etc., etc.

We where happy when we could find an full synthetic that could last for over 5,000 miles in one………..on the street.

...

Hey JFP,

Like I asked - can you point me to the UOAs or a spreadsheet of them? I'm not trying to be facetious here, nor am I trying to represent myself as an expert on the m96. I don't have access to a bunch of m96 UOAs either (short of lots of google searching).

My short google search led me to other postings of yours with similar statements. Frankly, my exchanges with lubrication engineers (specifically, automotive oils for street use) have led me to argee with you that several Mobil oils are terrible....but their 0w40 and 15w50 synthetic blends are top notch. Their 0w40 DOES shear down to a 0w30, but from what I can tell it was always intended to be a 0w30 and had VIIs added to bring it to 0w40 for european spec requirements, not to make it a better lubricant.

My understanding is that the m96 is, short of the early design problems and the IMS, a very well built and designed engine with very few problem areas within the lubricated & reciprocating masses. So your statements about oil passages clogging, chain tensioners, and dry bearings catch me somewhat by surprise. Are those common failure points in these engines? If so, ok, good to know.

Also, my statements regarding boxers being easy on oil was, as was stated and intended, a generalization. Boxer engines in general tend to REQUIRE less oil because of the shorter paths to return and the less time spent by oil getting heat and more time spent in cooler areas or in the general sump. That, combined with the very large sump in the m96, combined with my general understanding of the m96 being a very bulletproof engine and not having alot of lubricated-part failures...well, you can see my inferences.

I would truly love to dig through those UOAs if you can point me in the direction. Also, I'll reconsider what oil I choose to put in my boxster if your data indicates such consideration is warranted.

[thstone]

I'm using Mobile 1 10W40 High Mileage. I read that it has a high concentration of wear protectors and high temp shear strength. And I can get it at any local autoparts store.

I am changing it at 5,000 miles or 6 months (which is about the same for me). Why? Because its not a big cost issue to me to change the oil more frequently ($200 per year vs $100 per year).

Also, my own personal vehicle ownership experience says that using a good oil and changing it frequently is always a winning strategy (e.g. my 1991 Nissan Pathfinder that I sold to my nephew with 225,000 miles is still running fine at 340,000).

[JFP in PA]

Like I asked - can you point me to the UOAs or a spreadsheet of them? I'm not trying to be facetious here, nor am I trying to represent myself as an expert on the m96. I don't have access to a bunch of m96 UOAs either (short of lots of google searching).

We have collected, at our customer's expense, a significant amount of UoA data in a SQL database spanning a very long time frame. During that time, we have been able to see the impact of product reformulations, and in some cases the degradation, of what were once top notch products. As such, the data represents the intellectual property of both my business and that of my customers, by prior agreement. While I have, from time to time, "published" some excerpts of the data in thread exchanges on this site and others, I am not about to provide free access to what has take years to acquire at considerable expense, primarily because of the potential legal issues involved (some companies just love to sue, even when they are wrong and you can prove it), and because history has repeatedly demonstrated that such disclosures simply start meaningless, and typically unsubstantiated arguments. If you have a specific question, I will attempt to provide an answer, with supporting data.

My short google search led me to other postings of yours with similar statements. Frankly, my exchanges with lubrication engineers (specifically, automotive oils for street use) have led me to argee with you that several Mobil oils are terrible....but their 0w40 and 15w50 synthetic blends are top notch. Their 0w40 DOES shear down to a 0w30, but from what I can tell it was always intended to be a 0w30 and had VIIs added to bring it to 0w40 for european spec requirements, not to make it a better lubricant.

A one point, Mobil 1 0W-40 was a pretty decent oil, but ever since Exxon acquired Mobil, it has been going down hill. When first introduced, is was suspected that this product was a true Group IV based oil, but as it has gone thru several reformulations, no one really knows what it is currently. It is known that the most recent version took multiple attempts to get it to pass the ACEA A3, B3, B4 specs, and then only barely. The 15W-50, once a mainstay of the air-cooled crowd, no longer carries any ACEA ratings, as backed up by its equally dismal UoA’s. Hardly what I would call stellar performance.

My understanding is that the m96 is, short of the early design problems and the IMS, a very well built and designed engine with very few problem areas within the lubricated & reciprocating masses. So your statements about oil passages clogging, chain tensioners, and dry bearings catch me somewhat by surprise. Are those common failure points in these engines? If so, ok, good to know.

Lifter and chain tensioner noise and collapsed lifter issues are a constantly reoccurring theme on technical sites such as RennTech and over at Jake Raby’s FlatSixInnovations sites. Oil starvation under hard cornering has also claimed more M96’s than most would believe, do a search for track related failures and I’m sure you find plenty of interesting reading. Short of an M96 with the factory X51 option (which added a deeper sump and a “North West Passage” oil return from an additional scavenging pump), hard track time requires an Accusump at a minimum….

Also, my statements regarding boxers being easy on oil was, as was stated and intended, a generalization. Boxer engines in general tend to REQUIRE less oil because of the shorter paths to return and the less time spent by oil getting heat and more time spent in cooler areas or in the general sump. That, combined with the very large sump in the m96, combined with my general understanding of the m96 being a very bulletproof engine and not having alot of lubricated-part failures...well, you can see my inferences.

I would truly love to dig through those UOAs if you can point me in the direction. Also, I'll reconsider what oil I choose to put in my boxster if your data indicates such consideration is warranted.

Heat is a far bigger issue than you give it credit for. Most M96’s typically run well over 210F in relatively cool conditions on the street (the dash display is notoriously inaccurate and non linear in its readings). Add to that the number of internal “hot spots” within the cooling system, and you have questionable oils running at excessively high average operating temps. You also have, as noted by others, a cooling system using an impeller design the often leads to debris plugged cooling passages, raising the engines internal heat levels to the point that head cracking is a common event. Not exactly what comes to mind when someone says “bullet proof”…………..

[Jake Raby]

:ah:
So many tribologists...

[JoeFromPA]

Thanks JFP. To be blunt but not to be insulting, when you were stating you had an extensive collection of UOAs but weren't linking to it, I was starting to wonder what I was missing out on. Now I understand, and respect that.

Below is my take on UOA as a tool for analyzing oil effectiveness, read or ignore as you wish as its my own opinion:

Here's a few things I've learned from about 4 years of amateur oil analysis for myself and many others: UOAs are almost meaningless, in terms of wear metals. Countless hours of discussion go into iron PPM, or lead, or copper. But it comes down to wear metals being meaningless. Wear metals in a UOA are a reflection of a narrow range of dissolved metal particle size, and can be influenced by a single particle streak off one bearing that's an isolated event.

Things I think are important but reflective of car condition are typically Silicon, Potassium, and Sodium. I don't care about UOA-based analysis of additive package...for example, levels of zinc and phosphorous in UOAs are almost meaningless outside of specific engine designs (such as flat tappet). Great if someone added boron suddenly, but at the end of the day the UOA doesn't actually tell you whether or not the additive package is superior or inferior.

...

In terms of analyzing oil effectiveness, I care about the following:
TBN and/or TAN content at a given mileage & time of use (vs. virgin if possible, though not critical)

Viscosity at a given mileage & time of use

Insoluble level (for filtration analysis)

- That's it for me. Anything else is almost completely useless for interpretation.

...

So, if you are willing to share, I'd ask this: do you have at least 3+ 986 UOAs that used an oil for 7000-8500 miles within a period of 9 months, were regularly driven and had no track time, and that sheared the following:

M1 0w40 down to a 20 grade
M1 15w50 down to a 30 grade

or some other combination that dropped 2 grades, and at the same time had a fuel content of 2% or less?

I understand about heat - what's the typical driving temp of the boxster? Almost all modern synths can withstand 240-250 all day long without degradation, for 7.5k miles or longer. However, I understand your point about spot heat....impossible to know it's true effect in the abstract.

Thanks for all your time

[JFP in PA]

Originally Posted by JoeFromPA

Thanks JFP. To be blunt but not to be insulting, when you were stating you had an extensive collection of UOAs but weren't linking to it, I was starting to wonder what I was missing out on. Now I understand, and respect that.

Below is my take on UOA as a tool for analyzing oil effectiveness, read or ignore as you wish as its my own opinion:

Here's a few things I've learned from about 4 years of amateur oil analysis for myself and many others: UOAs are almost meaningless, in terms of wear metals. Countless hours of discussion go into iron PPM, or lead, or copper. But it comes down to wear metals being meaningless. Wear metals in a UOA are a reflection of a narrow range of dissolved metal particle size, and can be influenced by a single particle streak off one bearing that's an isolated event.

Things I think are important but reflective of car condition are typically Silicon, Potassium, and Sodium. I don't care about UOA-based analysis of additive package...for example, levels of zinc and phosphorous in UOAs are almost meaningless outside of specific engine designs (such as flat tappet). Great if someone added boron suddenly, but at the end of the day the UOA doesn't actually tell you whether or not the additive package is superior or inferior.

...

In terms of analyzing oil effectiveness, I care about the following:
TBN and/or TAN content at a given mileage & time of use (vs. virgin if possible, though not critical)

Viscosity at a given mileage & time of use

Insoluble level (for filtration analysis)

- That's it for me. Anything else is almost completely useless for interpretation.

...

So, if you are willing to share, I'd ask this: do you have at least 3+ 986 UOAs that used an oil for 7000-8500 miles within a period of 9 months, were regularly driven and had no track time, and that sheared the following:

M1 0w40 down to a 20 grade
M1 15w50 down to a 30 grade

or some other combination that dropped 2 grades, and at the same time had a fuel content of 2% or less?

I understand about heat - what's the typical driving temp of the boxster? Almost all modern synths can withstand 240-250 all day long without degradation, for 7.5k miles or longer. However, I understand your point about spot heat....impossible to know it's true effect in the abstract.

Thanks for all your time

OK, here we go, per your preferred values:

The cars (986/987) using current 0W-40 Mobil 1, bone stock (no modifications to the cooling or oil systems, running OEM style filters), no known track time. For the following values, TBN's are expressed as a % retained of the baseline (virgin) values, viscosities are in cSt @ 100 C per ASTM D445, insoluble’s as % of total, fuel as % of total:

A: 2958 miles on the oil, retained TBN 41%, viscosity of 8.1, insoluble’s <0.1%, fuel <0.5%
B: 4870 miles, retained TBN 34%, viscosity of 7.3, insoluble’s of 0.2%, fuel <0.5%
C: 3570 miles, retained TBN 39%, viscosity of 7.7, insoluble’s of 0.15%, fuel <0.5%

986 on 15W-50 Mobil 1,bone stock (no modifications to the cooling or oil systems, running OEM style filters), no known track time.

D: 4655 miles, retained TBN 35%, viscosity of 9.6, insoluble’s of 0.2%, fuel <0.5%

For reference purposes, I would expect a 20W oil to demonstrate a viscosity of around 9.0 cSt @ 100C, and a 30W to be around 11.1 cSt @ 100C.

So much for the oil going 10,000 miles...............

[JFP in PA]

Gee, it suddenly got very quiet……………..

[Idaho Red Rocket 3]

So is Castrol Syntech the answer to the oil problem. Maybe Redline ?

[JFP in PA]

We prefer the Castrol Syntec over the Redline; in all but the extreme cold I would use 10W-40, if you live and drive in the Arctic, possibly the 5W-40, but you will need to change the lighter weight at no more than 5K miles, while the 10W-40 can go up to 7,500 in most street applications.

[jmatta]

Gee, it suddenly got very quiet……………..

Kind of hard to argue with data...thanks for keeping us "lay people" informed.

[JFP in PA]

Originally Posted by jmatta

Gee, it suddenly got very quiet……………..

Kind of hard to argue with data...thanks for keeping us "lay people" informed.

Anytime......

[danyl55]

Originally Posted by JFP in PA

We prefer the Castrol Syntec over the Redline; in all but the extreme cold I would use 10W-40, if you live and drive in the Arctic, possibly the 5W-40, but you will need to change the lighter weight at no more than 5K miles, while the 10W-40 can go up to 7,500 in most street applications.

-- thanks JFP--

[mts]

Originally Posted by JFP in PA

Gee, it suddenly got very quiet……………..

Jeff thanks for the data. Your results mirror those from my local Porsche specialist and a local engine builder (non-Porsche). I'm always glad to have some additional confirmation.

[JoeFromPA]

JFP - I hadn't logged in in 4 days after checking later in the day for your response. My apologies that I apparently seem "suspicious" in my lack of immediate response.

Your data looks solid and shows a fairly ridiculous level of shearing in the period of time shown. The TBN retention is misleading - TBN tends to decrease drastically immediately, and then settle in.

Nonetheless, it's troubling. I've seen M1 0w40 shear down to a 20 grade plenty of times, and not affect notable engine life, but that was after an extended run. I think its known to shear down to a 20 grade in the DI Audi/VW 2.0t engine, but that engine even eats up redline 5w40 in 5k miles.

I'm sorry to say that after 20 minutes of googling, I can't find a single boxster 2.5 liter UOA to gain any personal insight on beyond what you've shared. So I'll take your words as wisdom until I find either further reinforcing evidence or something to dispute it.

Don't know if you care, but here's my own relevant history of UOAs:

Mobil One 15w50 in my 2008 Subaru Legacy GT (known for eating up oils) - Link to 15w50 UOA

60k miles of extended duration UOAs on my '06 Civic SI, up to its current usage of M1 0w40 for 13k: 06 Civic SI UOA series

I'm going to step out in a few minutes and, as a result of your UOAs, will buy either redline 5w40 (if I can find it) or M1 5w40 TDT instead of using my stock of 0w40.

I appreciate the time you've put into sharing this - I am not a blind shill to either side and though I'd prefer to see your data set, I also know you have a solid reputation here.

Thanks for taking the time to respond to me in depth.

[JFP in PA]

The problem with the TBN values lies in the fact that once an oil is past the 50% mark, it is well on its way out and should be changed (a 50% drop from baseline has long been considered by many as a "yardstick" for when to change the oil). So, yes, there is usually a pretty quick fall off, then a more tapered decrease; but the 50% yardstick still holds regardless of the drop off rate, plus other brand oils do not show this level of drop off is so few miles in the same vehicles. And, as others have posted, we are not the only ones seeing this level of performance. Plus, not everyone that keeps data on oil performance makes it available to a Google search…..

As for an “X”W-40 oil shearing down to a viscosity equivalent to a 20 weight oil not being harmful, sorry, but I cannot agree with you. As Toyota recently discovered with their recommended use of 5W-20 oil in their large V8 pickups’ to get a better CAFÉ rating, premature engine replacements resulted in a mandated move to heavier weight oils.

Not every vehicle, or every oil change in a single vehicle, shows these levels of degradation with Mobil 1 0W-40; but it happens often enough to be very disconcerting. As a point in fact, one of the very worst M1 0W-40 oil performances we have seen to date was in a new Cadillac that was used as a luxury soccer-mom vehicle; kind of the last place you would expect an oil to crap out quickly. But it did.

[JoeFromPA]

The Caddy you mention has GM's 3.6 liter DI engine, correct? That engine is doing horrible things to all oils. I don't believe even RLI's 5w40 has been able to withstand shearing in it, and that was the one oil that was holding up to the RS4's engine (albeit for moderate run lengths)

As far as TBN and 50% of baseline,that's bunk as far as I know. Almost all oils will fall down by 50% within 5k miles. Amsoil SSO, which has a baseline TBN of 12, doesn't stay at TBN 6 after 5-6k miles....despite being an oil rated for 15k-25k+ miles (by amsoil). Take my comments for whatever they are worth to you, but as far as I know TBN is fine until it starts to:

1. Reach 2.0-2.5 or below
2. Be very low in relation to TAN in a traditional oil (that doesn't apply to oils like RLI, which start with a high TAN from their basestock chemistry)

I understand proprietary datasets - makes alot of sense when developing something privately or for marketing purposes. Doesn't make alot of sense to me when using the data to advise the public. I'm not guessing which you are using yours for, I'm simply making a general observation.

Regarding shear and harm to engine: Toyota under-spec'd an oil and it did harm to the engine. That doesn't have a direct correlation to how a good oil will perform post-shear. BMW M's "famous" castrol 10w60 routinely shears down to a 30 grade in normal use, but it still protects those engines just fine. Other oils also shear routinely and protect fine. I'm not saying it's reassuring; I am observing that shear does not = enhanced engine wear.

If someone had a massive data set of UOAs on a particular engine, they could determine if the incidence of shear corresponded to a linear/exponential increase in particular wear metals. But it'd need to be substantial enough to be worthwhile. My .02

[JFP in PA]

The Caddy you mention has GM's 3.6 liter DI engine, correct? That engine is doing horrible things to all oils. I don't believe even RLI's 5w40 has been able to withstand shearing in it, and that was the one oil that was holding up to the RS4's engine (albeit for moderate run lengths)

All DFI engines oil suffers from problems related to excessive fuel intrusion, including Porsche; but some oils (those with ACEA A3/B4 and A5/B5 ratings, for example) do considerably better than other products in these applications. Unfortunately, far too many small "blenders" (including some you have mentioned) make marketing claims designed to indicate their products meet those specification, when in actual fact they do not; often holding no ACEA ratings at all as they do not participate in the ACEA testing protocols. That nonsense makes it difficult for the average consumer to understand what is real from what is marketing hype..... And, just for a reference point, we solved the Caddy's issues solely by switching it to a different brand and weight of oil. It now goes 6-7K miles between changes with no problems.

As far as TBN and 50% of baseline,that's bunk as far as I know. Almost all oils will fall down by 50% within 5k miles. Amsoil SSO, which has a baseline TBN of 12, doesn't stay at TBN 6 after 5-6k miles....despite being an oil rated for 15k-25k+ miles (by amsoil). Take my comments for whatever they are worth to you, but as far as I know TBN is fine until it starts to:

1. Reach 2.0-2.5 or below
2. Be very low in relation to TAN in a traditional oil (that doesn't apply to oils like RLI, which start with a high TAN from their basestock chemistry)

Cannot agree with you there; far too much data (and not just ours) says otherwise. One miss conception is that the use of synthetics automatically allows huge increases in mileage between changes, which is not necessarily the case. A more interesting comparison is the delta in TBN (or TAN) in relation to the change in viscosity, a strong indication of how the additives package is holding up to heat and shear. TBN values do a pretty good job of that. An oil that starts as a 0W-40 looks more like a 0W-20 (or worse) about the same time the TBN retention value drops below 50%. For a lot of highly touted "full synthetic" oils, that is no where near 6,000 miles. That alone is why a lot of Porsche engine builders are telling their clients to change the oil much more frequently; often in the 3,500 to 5,000 mile ranges. The "delta" values are much more important than you give them credit for.

I understand proprietary datasets - makes alot of sense when developing something privately or for marketing purposes. Doesn't make alot of sense to me when using the data to advise the public. I'm not guessing which you are using yours for, I'm simply making a general observation.

In the repair shop industry, customers pay you for what you know, as well as what you can do for them. Quite often the knowledge portion is hard to come by, as well as very expensive to obtain. Just about any decent tech in a shop knows "how to beat the flat rate book" without any sacrifice in the quality of their work; that is how they earn their living. But you would be hard pressed to find a book or website that tells you how they actually do it; that data is their "bread and butter". Years ago, it became very obvious that a lot of what the oil manufacturers (or blenders) were saying was not panning out in the real world. So, to quote an old Russian maxim, specialty shops took the position of "trust, but verify", and started testing programs on their own, and not just on engine oils. Quite often, the results could only be described as "eye opening". And that information obviously has considerable commercial value; if someone asks you for your recommendation on oil change intervals on weight "A" vs. weight "B" of brand "X" oil, you can give them an answer based upon data rather than intuition, knowing that your answer will be a safe one and not come back to haunt you. But that does not mean that I (or anyone else in the trade) intend to post that data on some website; while I do not have any issues answering a question (with some supporting data) on a website, at the end of the day, I do like to eat well.

Regarding shear and harm to engine: Toyota under-spec'd an oil and it did harm to the engine. That doesn't have a direct correlation to how a good oil will perform post-shear. BMW M's "famous" castrol 10w60 routinely shears down to a 30 grade in normal use, but it still protects those engines just fine. Other oils also shear routinely and protect fine. I'm not saying it's reassuring; I am observing that shear does not = enhanced engine wear.

You do realize that BMW went to the 10W-60 only after a significant number of their M3 engines prematurely croaked on lighter weight oils? The 10W-60 was "band-aid" to keep them from having to warranty even more engines than they already had done for crankshaft related failures due in some measure to their choice of a lighter oil to try and get CAFE rates up, which is exactly what Toyota did, with similar results. The only apparent differences were that more M3 owners ********************ed about it on websites, and threatened lawsuits, than Toyota pickup owners did; and that the 10W-60 oil took a lot longer to shear down to the "danger zone" weight than their original weight recommendation oil did. But even the 10W-60 can get there given enough time.

If someone had a massive data set of UOAs on a particular engine, they could determine if the incidence of shear corresponded to a linear/exponential increase in particular wear metals. But it'd need to be substantial enough to be worthwhile. My .02

They could, but to be completely meaningful, it would need to include more than just the UoA’s detected metals levels, you would need to know how those values relate to actual internal engine component conditions; which would require the tear down, examination, and careful weighing of critical components within the engines, and assuming that the OEM does not make significant component changes within given model years. And, like most OEM's, Porsche uses multiple vendors for most components, which would also need to be factored in, along with developing another dataset of where the critical wear materials "inflection points" are (the level of wear requiring further repair or replacement actions). This requires considerable resources, and is probably why Porsche requires their dealer network to return failed engines to Germany for evaluation. Unfortunately, such a program is well outside the resources of all but the most sophisticated specialty engine building shops; and definitely outside the resources of my business.

[danyl55]

ask a simple question and you get a................

[clickman]

Originally Posted by danyl55

ask a simple question and you get a................

Originally Posted by JFP in PA

We prefer the Castrol Syntec over the Redline; in all but the extreme cold I would use 10W-40, if you live and drive in the Arctic, possibly the 5W-40, but you will need to change the lighter weight at no more than 5K miles, while the 10W-40 can go up to 7,500 in most street applications.

Can't answer your question any better. And if you were expecting a simple answer to this question, you haven't spent much time on these forums. There are hundreds of threads on this topic. This one at least gives some technical background to those that might have the interest.

[JoeFromPA]

Agreed. And though I don't agree with JFP on some of the technical points, such as DPN depletion rates, I do bow to his vastly superior apparent resource base and knowledge of this particular engine.

To the point where I'm going to either buy castrol or buy another oil and start doing UOAs, but I'll skip using my 0w40 at this stage.