oil for a 1997 Boxster

[JoeFromPA]

Some individuals feel that changing the oil too frequently is a bad thing, as it increases the likelihood of something going wrong (oil filter housing coming loose, contamination at top of engine).

The other reason is that oil has the most volatile compounds when new, which breakdown in the first few hundred/thousand miles. After that, it tends to be in quite good shape for a long time in terms of stability.

Neither of those reasons really apply, in my opinion, to oil changes that are at least 1000 miles apart.

On the flip side, there is no reason why high-end oils (such as M1 0w40) should be replaced at 5k miles in the m96 (unless it's been well over a year, or it was 5k of the most brutal miles). The m96 is not that brutal of an engine by any standard, and it has a massive sump size full of high-end oil....

Sump size matters alot in these things.

[Lobo1186]

to put into perspective the size of the sump in the m96, it takes about 9qt of oil. ranging from 2.5-3-4L for motor size.

the dodge viper has TEN cylinders ranges from 8-8.4 liters and at least in the 2002, it takes 10qt.

[clickman]

Originally Posted by JoeFromPA

there is no reason why high-end oils (such as M1 0w40) should be replaced at 5k miles in the m96 (unless it's been well over a year, or it was 5k of the most brutal miles).

Experts doing used oil analysis will tell you otherwise...

[Brucelee]

Red Line.

Expensive but worth it.

[JoeFromPA]

Originally Posted by clickman

Experts doing used oil analysis will tell you otherwise...

Hi Clickman,

I consider myself an expert oil analyst (amateur, I'm not a professional). Can you point me in the direction of any oil analyses indicating the m96 eats high-end synthetics in even 7-8k miles?

To get such info from an oil analysis, you would need to have one or more of the following consistently appearing in m96 oil analyses by the ~7.5k mark:

- Xw40 oils degrading down to a 20 grade viscosity
- TBN is gone, or TAN is exceptionally high
- Insolubles are too high

Almost none of those are feasible when we're talking about 8.5 quarts of high-end synthetic in a naturally aspirated small displacement engine, daily driven or similar, with any form of modern filtration. Furthermore, boxer engines are typically very easy on oil by their design.

Now, maybe there is some sort of engine-oil lubricated bearing point that is absolutely brutal on engine oils in the boxster. However, I've never heard of that and, if that was the case, you'd hear about a common oil-lubricated bearing failure point due to the unusual stresses involved.

The engine-oil lubricated parts of the boxster are exceptionally sound, in part because they are not very stressful to interacting parts protected by a thin layer of oil.

Hope that all made sense.

[JFP in PA]

Originally Posted by JoeFromPA

To get such info from an oil analysis, you would need to have one or more of the following consistently appearing in m96 oil analyses by the ~7.5k mark:

- Xw40 oils degrading down to a 20 grade viscosity
- TBN is gone, or TAN is exceptionally high
- Insolubles are too high

Almost none of those are feasible when we're talking about 8.5 quarts of high-end synthetic in a naturally aspirated small displacement engine, daily driven or similar, with any form of modern filtration. Furthermore, boxer engines are typically very easy on oil by their design.

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.

[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).

[JoeFromPA]

5 quart bottles of 10w40 Castrol Syntec are at Walmart for $21.

I bought 2 for $42 + an oil filter. Figure with tax, $60 for an oil change.

At that price range, and with what JFP has stated, it was an easy choice for this year. I may even toss in $35 at the end of the year to do a UOA.

[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...