997.2 Oil Consumption
04-21-2009, 02:54 PM
#31
Race Director
I can't believe Porsche considers 1.6 quarts per 620 miles acceptable.
That would be 16 quarts of oil per standard oil change schedule of about 6000 miles.
That would be 16 quarts of oil per standard oil change schedule of about 6000 miles.
04-21-2009, 03:01 PM
#32
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1999Porsche911,
If you had simply stated that you use "Mobile Molasses" instead of "Mobile Water," we would have understood.
If you had simply stated that you use "Mobile Molasses" instead of "Mobile Water," we would have understood.
04-21-2009, 03:10 PM
#33
Race Car
It used to be 1 quart for every 600 miles. Due to excessive complaints from owners, Porsche was forced to looked into the matter. To resolve the issue, they simply raised the allowable amount of oil we can all burn.
If further adjustments are needed to what amount of oil burning is acceptable, no doubt that a new TSB will be issued.
Only a Porsche owner would accept a car with an engine with such loose tolerances. Porsche knows this, so why should they spend money making a better engine?
04-21-2009, 04:04 PM
#34
Ironman 140.6
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Your most from above??????
Originally Posted by 1999Porsche911
I did not say that oil weight causes oil burning.
You did not say it outright, but you certainly implied it. I'm glad you have clarified that excess oil consumption is not caused by lower weight oil.
Then I misunderstood. I thought you were going to recommend an oil outside of Porsche's published list as you have done in the past.
I believe Porsche does have one 5W-50 on its list.
What oil to run depends on the climate. For climates where temperatures are normally above 30F, I would not run anything less than a 50 weight oil, such as a 5W50 or 15W50. Mobil's EXTENDED PERFORMANCE 15W50 is what I use in my high compression engines.
Have you ever noticed that Mobil states that their EXTENDED PERFORMANCE oils are "........compatible with engine seals" but don't address the seals in marketing their 0W40?
Originally Posted by 1999Porsche911
I did not say that oil weight causes oil burning.
You did not say it outright, but you certainly implied it. I'm glad you have clarified that excess oil consumption is not caused by lower weight oil.
Then I misunderstood. I thought you were going to recommend an oil outside of Porsche's published list as you have done in the past.
I believe Porsche does have one 5W-50 on its list.
What oil to run depends on the climate. For climates where temperatures are normally above 30F, I would not run anything less than a 50 weight oil, such as a 5W50 or 15W50. Mobil's EXTENDED PERFORMANCE 15W50 is what I use in my high compression engines.
Have you ever noticed that Mobil states that their EXTENDED PERFORMANCE oils are "........compatible with engine seals" but don't address the seals in marketing their 0W40?
Temper, temper and I thought we were having a reasonable conversation.
15w50 is not an oil that Porsche recommends for these cars. I know I've heard you say it's all marketing, but Mobil 1 does have a 15w50 oil and it's not on the list either.
The fact is (feel free to correct me if I'm wrong) you never done any wear testing on the Porsche motors being discussed in this thread (997.2 DI motors or any of the earlier 996.2 or 997.1 variocam plus motors). You've never extensively tested the affects of different oil viscosity on variocam plus function.
Instead, you typically bring a lot of anecdotal evidence of the sort that this is what I use in my '99 996 and it works for me as I have no oil leaks, RMS problems, excessive oil usage, etc. so I must have found the magic cure that Porsche is too dumb to see because they’re too busy collecting marketing payoffs from Mobil.
Guess what, I'm no oil expert and I don't run around claiming to be one. That being said, I did stay in a Holiday Inn once so I'll throw out my $.02.
Not being an expert, my first inclination on the subject is to look to those that are for their thoughts on the matter.
First there is Porsche. They go through the trouble to test their cars prior to sale and publish a list of oils that they recommend for the cars that they built.
Second, there are independent Porsche experts that seem to agree with Porsche. In Excellence magazine for example the editors published the following when asked this question in 2007;
a reader asked a question about using 10W-40 oil (for a Boxster) in Florida vs Mobil 0W-40. He is concerned about using the 0W-40 because 10W-30 or 10W-40 is a "more common fill" in Florida (he also asks about break-in). The response from the Excellence technical expert was as follows.
"Those who suggest higher viscosity oils usually don't understand the whole problem. Oil in engines is no longer just a lubricant. It is also a coolant for the engine as well as a hydraulic control fluid for all of the things like VarioCam Plus, hydraulic lifters, and similar systems. If the oil is too high a viscosity, it can affect the way those circuits operate.
The 2001 996 Turbo was the first Porsche to use the VarioCam Plus technology and a friend who works as a dealer technician told me that one of their technicians spend the whole day trying to diagnose a running problem caused by an owner who hadn't trusted Porsches factory fill and thus changed his oil to SAE 20W-50. The heavier oil totally confused the VarioCam plus system and the engine ran poorly.
All of these devices have been designed to run with the SAE 0W-40 oils or other oils that Porsche recommends. Use only those oils recommended in your owners manual - SAE 0W-40, SAE 5W-40, or SAE 5W-50. Porsche is so sure about this decision that it came out with a bulletin recommending these oils for all of its older models as well."
The late Jim Pasha said this on the subject;
"Why does Porsche specify such a low lower viscosity rating? The answer comes in two parts. First, in a quest for better fuel economy and longer engine life, Porsche engineers use bearing and cylinder-wall clearances far tighter than what they used previously. This creates less internal drag on components, and lighter oil is more compatible with tight tolerances."
He also reported
"In the latest Porsches, which use 0W-40, the thinner oil is critical to delicate systems that use motor oil as a hydraulic activator. VarioCam Plus uses tiny "shafts" of oil created under high pressure to help the system alter valve timing. It is a trick system but it REQUIRES thin oil to work properly
So, who should I trust? On one hand I've got the people who built the cars (and admittedly they have not always proven to be prefect) and experts that write about and work on these cars.
On the other hand I have you who has been running around every oil thread on Rennlist for the past several years professing the evils of thinner oil.
As I stated, I'm not an expert. Do you have any research to support you hypothesis about all the evils of using thinner oils in the late model Porsche's that are being discussed here?
04-21-2009, 04:07 PM
#35
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04-21-2009, 04:17 PM
#36
Ironman 140.6
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04-21-2009, 04:25 PM
#37
Race Director
From my experience with other makes, 1qt per 1000 miles was the absolute limit of oil consumption.
Pretty much no high end auto that I've owned burned excessive oil, with the exception of the 2000 M5. That thing ate 10w-60 with regularity.
Pretty much no high end auto that I've owned burned excessive oil, with the exception of the 2000 M5. That thing ate 10w-60 with regularity.
04-21-2009, 05:01 PM
#38
Race Car
Temper, temper and I thought we were having a reasonable conversation.
15w50 is not an oil that Porsche recommends for these cars. I know I've heard you say it's all marketing, but Mobil 1 does have a 15w50 oil and it's not on the list either.
The fact is (feel free to correct me if I'm wrong) you never done any wear testing on the Porsche motors being discussed in this thread (997.2 DI motors or any of the earlier 996.2 or 997.1 variocam plus motors). You've never extensively tested the affects of different oil viscosity on variocam plus function.
Instead, you typically bring a lot of anecdotal evidence of the sort that this is what I use in my '99 996 and it works for me as I have no oil leaks, RMS problems, excessive oil usage, etc. so I must have found the magic cure that Porsche is too dumb to see because they’re too busy collecting marketing payoffs from Mobil.
Guess what, I'm no oil expert and I don't run around claiming to be one. That being said, I did stay in a Holiday Inn once so I'll throw out my $.02.
Not being an expert, my first inclination on the subject is to look to those that are for their thoughts on the matter.
First there is Porsche. They go through the trouble to test their cars prior to sale and publish a list of oils that they recommend for the cars that they built.
Second, there are independent Porsche experts that seem to agree with Porsche. In Excellence magazine for example the editors published the following when asked this question in 2007;
a reader asked a question about using 10W-40 oil (for a Boxster) in Florida vs Mobil 0W-40. He is concerned about using the 0W-40 because 10W-30 or 10W-40 is a "more common fill" in Florida (he also asks about break-in). The response from the Excellence technical expert was as follows.
"Those who suggest higher viscosity oils usually don't understand the whole problem. Oil in engines is no longer just a lubricant. It is also a coolant for the engine as well as a hydraulic control fluid for all of the things like VarioCam Plus, hydraulic lifters, and similar systems. If the oil is too high a viscosity, it can affect the way those circuits operate.
The 2001 996 Turbo was the first Porsche to use the VarioCam Plus technology and a friend who works as a dealer technician told me that one of their technicians spend the whole day trying to diagnose a running problem caused by an owner who hadn't trusted Porsches factory fill and thus changed his oil to SAE 20W-50. The heavier oil totally confused the VarioCam plus system and the engine ran poorly.
All of these devices have been designed to run with the SAE 0W-40 oils or other oils that Porsche recommends. Use only those oils recommended in your owners manual - SAE 0W-40, SAE 5W-40, or SAE 5W-50. Porsche is so sure about this decision that it came out with a bulletin recommending these oils for all of its older models as well."
The late Jim Pasha said this on the subject;
"Why does Porsche specify such a low lower viscosity rating? The answer comes in two parts. First, in a quest for better fuel economy and longer engine life, Porsche engineers use bearing and cylinder-wall clearances far tighter than what they used previously. This creates less internal drag on components, and lighter oil is more compatible with tight tolerances."
He also reported
"In the latest Porsches, which use 0W-40, the thinner oil is critical to delicate systems that use motor oil as a hydraulic activator. VarioCam Plus uses tiny "shafts" of oil created under high pressure to help the system alter valve timing. It is a trick system but it REQUIRES thin oil to work properly
So, who should I trust? On one hand I've got the people who built the cars (and admittedly they have not always proven to be prefect) and experts that write about and work on these cars.
On the other hand I have you who has been running around every oil thread on Rennlist for the past several years professing the evils of thinner oil.
As I stated, I'm not an expert. Do you have any research to support you hypothesis about all the evils of using thinner oils in the late model Porsche's that are being discussed here?
It might be easier for you to look at the facts individually:
All oils of the same class must meet SAE standards
These oils must fall within a limited range for each viscosity
The first number in oil’s viscosity rating is for cold start only. This rating is irrelevant when the oil is at 212F
The second number is the viscosity of the oil at 212F
ALL oils rated ?W50 have the same viscosity at 212F
If you accept the above as facts, you cannot successfully argue that straight 50 weight oil or a 20W50 oil will not function properly in the variocam system since Porsche says 5W50 oil works fine.
If you don’t believe these as facts, then you are left to follow whatever guidance you choose.
04-21-2009, 05:44 PM
#39
Drifting
It used to be 1 quart for every 600 miles. Due to excessive complaints from owners, Porsche was forced to looked into the matter. To resolve the issue, they simply raised the allowable amount of oil we can all burn.
If further adjustments are needed to what amount of oil burning is acceptable, no doubt that a new TSB will be issued.
Only a Porsche owner would accept a car with an engine with such loose tolerances. Porsche knows this, so why should they spend money making a better engine?
If further adjustments are needed to what amount of oil burning is acceptable, no doubt that a new TSB will be issued.
Only a Porsche owner would accept a car with an engine with such loose tolerances. Porsche knows this, so why should they spend money making a better engine?
If burning large amounts of oil leads to reliability problems down the road, THEN I have a problem. If the oil usage of 1qt per 1k miles means my engine's life expectancy is 1/2 that of one that burns 1 qt every 3k miles, THEN I have a problem.
All I want to know is: Do I have a problem. I don't care about how much oil I feed the thing.
In my case, a Oct 08 build Targa 4, it has gone through 1+ qts in 2000 miles. Put in a quart somewhere around 1100 and then the dealer put in some when I had it in the shop and asked about the right way to measure the oil level. They didn't say how much they put in.. could have been another quart for all I know.
04-21-2009, 05:46 PM
#40
Ironman 140.6
Rennlist Member
Rennlist Member
It might be easier for you to look at the facts individually:
All oils of the same class must meet SAE standards
These oils must fall within a limited range for each viscosity
The first number in oil’s viscosity rating is for cold start only. This rating is irrelevant when the oil is at 212F
The second number is the viscosity of the oil at 212F
ALL oils rated ?W50 have the same viscosity at 212F
If you accept the above as facts, you cannot successfully argue that straight 50 weight oil or a 20W50 oil will not function properly in the variocam system since Porsche says 5W50 oil works fine.
If you don’t believe these as facts, then you are left to follow whatever guidance you choose.
All oils of the same class must meet SAE standards
These oils must fall within a limited range for each viscosity
The first number in oil’s viscosity rating is for cold start only. This rating is irrelevant when the oil is at 212F
The second number is the viscosity of the oil at 212F
ALL oils rated ?W50 have the same viscosity at 212F
If you accept the above as facts, you cannot successfully argue that straight 50 weight oil or a 20W50 oil will not function properly in the variocam system since Porsche says 5W50 oil works fine.
If you don’t believe these as facts, then you are left to follow whatever guidance you choose.
I just rechecked the list and it appears there are no 50 weight oils on it anymore (the earlier list had only one).
This list (which is dated after and thus replaces the earlier list) contains none.
http://kiyor32.cocolog-nifty.com/gt3...-List-2006.pdf
It looks like Porsche has removed 50 weights. Still think a 50 is the way to go?
Edit....It looks like one oil out of 84 is a 50w (M1 5w-50).
04-21-2009, 05:47 PM
#41
Race Car
I just rechecked the list and it appears there are no 50 weight oils on it anymore (the earlier list had only one).
This list (which is dated after and thus replaces the earlier list) contains none.
http://kiyor32.cocolog-nifty.com/gt3...-List-2006.pdf
It looks like Porsche has removed 50 weights. Still think a 50 is the way to go?
This list (which is dated after and thus replaces the earlier list) contains none.
http://kiyor32.cocolog-nifty.com/gt3...-List-2006.pdf
It looks like Porsche has removed 50 weights. Still think a 50 is the way to go?
Sure do. And Porsche agrees. I doubt that they will ever remove 50 weight from their list.
04-21-2009, 05:54 PM
#42
Race Car
If burning a quart of oil every 700mi is the way these engines run and thats not an indication of a bigger problem, then I'm fine with putting the oil in. It is a marginal cost of driving a very fine machine. I'll add 1 qt every 1k miles for the next 300k miles, no problem.
If burning large amounts of oil leads to reliability problems down the road, THEN I have a problem. If the oil usage of 1qt per 1k miles means my engine's life expectancy is 1/2 that of one that burns 1 qt every 3k miles, THEN I have a problem.
All I want to know is: Do I have a problem. I don't care about how much oil I feed the thing.
In my case, a Oct 08 build Targa 4, it has gone through 1+ qts in 2000 miles. Put in a quart somewhere around 1100 and then the dealer put in some when I had it in the shop and asked about the right way to measure the oil level. They didn't say how much they put in.. could have been another quart for all I know.
If burning large amounts of oil leads to reliability problems down the road, THEN I have a problem. If the oil usage of 1qt per 1k miles means my engine's life expectancy is 1/2 that of one that burns 1 qt every 3k miles, THEN I have a problem.
All I want to know is: Do I have a problem. I don't care about how much oil I feed the thing.
In my case, a Oct 08 build Targa 4, it has gone through 1+ qts in 2000 miles. Put in a quart somewhere around 1100 and then the dealer put in some when I had it in the shop and asked about the right way to measure the oil level. They didn't say how much they put in.. could have been another quart for all I know.
04-21-2009, 05:56 PM
#43
Ironman 140.6
Rennlist Member
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04-21-2009, 05:59 PM
#44
Ironman 140.6
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04-21-2009, 06:00 PM
#45
Race Car
Don't forget that the approved list is pay to play and it can get pretty expensive to keep your name on the list. Many manufacturers don't think it is worth it.