Yet another engine viscocity question
08-27-2007, 08:02 PM
#76
Hi Doug,
Thanks for the input but I still am at a loss as to what oil do I use in my car.
Based upon the great information you posted about oils, I and two of my close friends changed to
Delvac 5W 40. Just so you understand where I am coming from, I have the greatest respect for you and your superior knowledge.
All three of us are experianceing LOP lights when in the past years we have had no such problem.
Inacurate gauge or not - we are seeing different readings since we change to 5W 40. Not good I am sure you would agree.
I just opened my 93 GTS owners manual and looked to find out what Mr. P recommends for my car.
With respect to multigrade oils he states that for a temp range of -10C to +40C I should be using a
20W 40 or 20W 50. These tempertatures best resemble what we experiance here in Texas.
So being the simple guy that I am, using 5W 40 is not what Mr. P intended for my car.
Am I correct in saying that I should be using one of these two weights of oils?
Because if so even 15W 50 is not correct for this climate in DFW.
Does anyone sell a 20W 40 or 20W 50?
Thanks,
Roger
Thanks for the input but I still am at a loss as to what oil do I use in my car.
Based upon the great information you posted about oils, I and two of my close friends changed to
Delvac 5W 40. Just so you understand where I am coming from, I have the greatest respect for you and your superior knowledge.
All three of us are experianceing LOP lights when in the past years we have had no such problem.
Inacurate gauge or not - we are seeing different readings since we change to 5W 40. Not good I am sure you would agree.
I just opened my 93 GTS owners manual and looked to find out what Mr. P recommends for my car.
With respect to multigrade oils he states that for a temp range of -10C to +40C I should be using a
20W 40 or 20W 50. These tempertatures best resemble what we experiance here in Texas.
So being the simple guy that I am, using 5W 40 is not what Mr. P intended for my car.
Am I correct in saying that I should be using one of these two weights of oils?
Because if so even 15W 50 is not correct for this climate in DFW.
Does anyone sell a 20W 40 or 20W 50?
Thanks,
Roger
When we spoke last, I believe I mentioned Schaeffer Oil as an alternative to the other 15w50 or 20w50 oils that are available. They've been around for over 100 years, selling high grade lubricants to ag & heavy industry. I dont work (or schill) for Schaeffer, just had really good experiences with their motor oil and transmission fluids. Blackstone lab oil analysis has shown excellent results with Schaeffer 15w40 in my Ford diesel. Dyson Analysis suggested their motor oil contains high moly concentrations, as does RedLine, but at lower cost per quart. The moly helps lubricate & protect valve train components which on our cars (and my diesel) really take a beating. I pay around $4 a quart for oil, $5 for trans fluid.
The 20w50 info can be found here:
http://www.schaefferoil.com/705_racing_oil.html
http://www.schaefferoil.com/datapdf/705.pdf
Trans fluid (as in Dexron II compatible) here:
http://www.schaefferoil.com/204_transmission_fluid.html
http://www.schaefferoil.com/datapdf/204SAT_r.pdf
Hawk
08-28-2007, 06:43 AM
#77
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Rennlist Member
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Am I missing something ?
The subject seems to be about hot oil pressure.
The "argument" seems to be about wether 0W or 5W is/was recommended or not.
I'm just an ignorant Structural injuneer but my simple understanding of the SAE classifications is that t'other number ie the bigger one is the one that dictates hot viscosity ie 30 or 40 or 50 generally (I note Penrite here in OZ produces oils up 70!).
Maybe someone can remind me what temperature the higher vicosity is measured at (I do recall that the lower number is a temperature not a viscosity). Is it possible that 928 oil temps at idle on a hot day in hotsville city arizona are hotter than the oil viscosity is measured at ? and further is it also possible that a true xxW/40 could actually retain that 40 viscosity at higher temperatures whereas a true xxW/50 could have a lower viscosity than the xxW/40 when subject to those temperatures ?
Where can I buy Amsoil in OZ - I am getting to the point that when the technical arguments diverge, Kibort's experience with the Holbert car proves something (so long as you don't care for your cam teeth) and it wouldn't really matter what Amsoil is made from it is proven to work.
The subject seems to be about hot oil pressure.
The "argument" seems to be about wether 0W or 5W is/was recommended or not.
I'm just an ignorant Structural injuneer but my simple understanding of the SAE classifications is that t'other number ie the bigger one is the one that dictates hot viscosity ie 30 or 40 or 50 generally (I note Penrite here in OZ produces oils up 70!).
Maybe someone can remind me what temperature the higher vicosity is measured at (I do recall that the lower number is a temperature not a viscosity). Is it possible that 928 oil temps at idle on a hot day in hotsville city arizona are hotter than the oil viscosity is measured at ? and further is it also possible that a true xxW/40 could actually retain that 40 viscosity at higher temperatures whereas a true xxW/50 could have a lower viscosity than the xxW/40 when subject to those temperatures ?
Where can I buy Amsoil in OZ - I am getting to the point that when the technical arguments diverge, Kibort's experience with the Holbert car proves something (so long as you don't care for your cam teeth) and it wouldn't really matter what Amsoil is made from it is proven to work.
08-28-2007, 08:08 AM
#78
Drifting
Hi Doug , thats just the point, you ( which I can undestand ) for many many years just look at the reems of information that eminate from oil companies and the like , which in its own context from the ivory tower seems fantastic to you and I can understand how you could be smitten by it all and all the promises from many companies, be it oil or anything else for that matter . But we and what I mean we I mean all the independant Porsche repair specialist that I know have in MANY MANY cases have followed the later religious cult following of using the thinner vis oils designed for the much later cars in these engines from last century,and all have had problems with low oil pressure and destroyed engines with bewildered customers , you dont know this because you have not had the hands on experience that we see nearly every day , and the most important aspect is WHEN THESE 928's were new WE HAD OIL PRESSURE PROBLEMS AT THE DEALER in hot weather in traffic situations, even GTS's ( these were new engines and they did not have worn out oil pressure relief valves or weak springs , and we had to do something and of course you were NOT there and you can not get real experience unless you are there in the field . And as you love an argument but you know full well in the field experience can not be taken out of a text book and the text ( written by someone else) that is ALL you have to offer , and in the case of the 928, Klaus Keastner who worked for Porsche AG in Germany from the early 1960's and right through their hay day of the 1970's and the 1980's , Klaus was one of the two Porsche Tech school teachers sent from germany By Porsche to teach at Porsche cars Australia in the mid 1980's. Klaus was generious in his knowledge to the students and I am very proud to say I became a good friend to him in his retirement years ( some years later ), and when I spoke to Klaus in person about this new idea of using oils out of ( what klaus called the original oil viscosity spectrum ) in other words what was originally specified by Porsche , he simply said to move away from this original spec will only result in much accelerated wear , and as he drummed in to me a 928 must never ever have its oil warning light on at idle , thats of course if you want it to enjoy any form of long life . But of course Doug you were not there in the field so I can see you are lacking in the fine art of hands on experience , but thats fine because thats life . Regards . BB .
08-30-2007, 12:25 AM
#79
Rennlist Member
Interesting about the oil comments of the x-porsche engineer!
AND, i have seen the mobil 1 cause the oil warning light to come on under race conditions . This seemed to magically go away with a change to another brand of oil.
superstitious or not, i dont think anyone could convince me of running Mobil 1, especially since i have had proven luck with Amzoil. again, no one in the world has more race miles on an original 928 race engine. Either the Holbert car has a miracle engine or Amzoil is responsible for this unusual long life of a engine used for racing. 6 seasons, 90 racing days, and always 5 bar at 260F, or 3.5 bar at idle.
MK
AND, i have seen the mobil 1 cause the oil warning light to come on under race conditions . This seemed to magically go away with a change to another brand of oil.
superstitious or not, i dont think anyone could convince me of running Mobil 1, especially since i have had proven luck with Amzoil. again, no one in the world has more race miles on an original 928 race engine. Either the Holbert car has a miracle engine or Amzoil is responsible for this unusual long life of a engine used for racing. 6 seasons, 90 racing days, and always 5 bar at 260F, or 3.5 bar at idle.
MK
Hi Doug , thats just the point, you ( which I can undestand ) for many many years just look at the reems of information that eminate from oil companies and the like , which in its own context from the ivory tower seems fantastic to you and I can understand how you could be smitten by it all and all the promises from many companies, be it oil or anything else for that matter . But we and what I mean we I mean all the independant Porsche repair specialist that I know have in MANY MANY cases have followed the later religious cult following of using the thinner vis oils designed for the much later cars in these engines from last century,and all have had problems with low oil pressure and destroyed engines with bewildered customers , you dont know this because you have not had the hands on experience that we see nearly every day , and the most important aspect is WHEN THESE 928's were new WE HAD OIL PRESSURE PROBLEMS AT THE DEALER in hot weather in traffic situations, even GTS's ( these were new engines and they did not have worn out oil pressure relief valves or weak springs , and we had to do something and of course you were NOT there and you can not get real experience unless you are there in the field . And as you love an argument but you know full well in the field experience can not be taken out of a text book and the text ( written by someone else) that is ALL you have to offer , and in the case of the 928, Klaus Keastner who worked for Porsche AG in Germany from the early 1960's and right through their hay day of the 1970's and the 1980's , Klaus was one of the two Porsche Tech school teachers sent from germany By Porsche to teach at Porsche cars Australia in the mid 1980's. Klaus was generious in his knowledge to the students and I am very proud to say I became a good friend to him in his retirement years ( some years later ), and when I spoke to Klaus in person about this new idea of using oils out of ( what klaus called the original oil viscosity spectrum ) in other words what was originally specified by Porsche , he simply said to move away from this original spec will only result in much accelerated wear , and as he drummed in to me a 928 must never ever have its oil warning light on at idle , thats of course if you want it to enjoy any form of long life . But of course Doug you were not there in the field so I can see you are lacking in the fine art of hands on experience , but thats fine because thats life . Regards . BB .
08-30-2007, 11:26 AM
#81
928 Collector
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Don't you think what CAUSED the light to come on was perhaps a low oil pressure condition?
08-30-2007, 11:30 AM
#82
Administrator - "Tyson"
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Trust me when I say nobody is trying to convince you to start using Mobil 1.
Problem is you strike fear into a lot of people about Mobil 1, that is unnecessary. So a few people like to point out Mobil 1 is just fine to counter your anti-Mobil 1 posts. Just keeping the balance.
Like I've said before, there are plenty of people I personally know running Mobil 1 in their track cars for many years with no issues.
Problem is you strike fear into a lot of people about Mobil 1, that is unnecessary. So a few people like to point out Mobil 1 is just fine to counter your anti-Mobil 1 posts. Just keeping the balance.
Like I've said before, there are plenty of people I personally know running Mobil 1 in their track cars for many years with no issues.
08-30-2007, 12:39 PM
#83
Rennlist Member
I know, i do feel a sense of obligation to show my results and experiences with the extreme use of my 928.
the "many years" of tracking, probably werent alll in 928s, were there? because i can name 15 grenaded 928s that have used Mobil 1.
THE only information i have been using is the lack of oil pressure when using mobil 1 on 3 different 928s. (yes, this caused the oil light to come on) when the oil was changed to amzoil, the issue went AWAY.
i use 20-50 Amzoil racing oil. (same results with kendal 20-50 racing oil as well or 20/50 redline)
companies have been using and misusing statistics for years. im not only showing a statistic, but an actual difference that is visible seen by looking at your oil pressure gauge when the oil is hot from track use (ie 260F oil temps)
Now, if you dont see these temps, probably any oil will do the job. But if you do, the contrarian opinion is that thin oil is ok, and might be actually better. well, then i go back to my statistics. 90 racing hours, 6 full racing seasons, no material in the filter, magnet, oil pressure good, compression same after 6 years, engine hp same, etc. Its just a testimonial, take it as such.
MK
the "many years" of tracking, probably werent alll in 928s, were there? because i can name 15 grenaded 928s that have used Mobil 1.
THE only information i have been using is the lack of oil pressure when using mobil 1 on 3 different 928s. (yes, this caused the oil light to come on) when the oil was changed to amzoil, the issue went AWAY.
i use 20-50 Amzoil racing oil. (same results with kendal 20-50 racing oil as well or 20/50 redline)
companies have been using and misusing statistics for years. im not only showing a statistic, but an actual difference that is visible seen by looking at your oil pressure gauge when the oil is hot from track use (ie 260F oil temps)
Now, if you dont see these temps, probably any oil will do the job. But if you do, the contrarian opinion is that thin oil is ok, and might be actually better. well, then i go back to my statistics. 90 racing hours, 6 full racing seasons, no material in the filter, magnet, oil pressure good, compression same after 6 years, engine hp same, etc. Its just a testimonial, take it as such.
MK
08-30-2007, 12:41 PM
#84
Rennlist Member
mobil 1 was determined to be the root cause of the oil light coming on at the track.
mobil 1 = thin oil at temp = lack of pressure= pressure sensor sees the lack of pressure= switch is engaged = switch turns on little red light at oil gauge.
MK
mobil 1 = thin oil at temp = lack of pressure= pressure sensor sees the lack of pressure= switch is engaged = switch turns on little red light at oil gauge.
MK
Really? You saw Mobil One CAUSE the oil warning light to come on? How did you determine that the oil brand CAUSED the light to come on? I have never heard of this. Amazing deductive reasoning. Or maybe the Amzoil CAUSED the light NOT to go on?
Don't you think what CAUSED the light to come on was perhaps a low oil pressure condition?
Don't you think what CAUSED the light to come on was perhaps a low oil pressure condition?
08-30-2007, 01:48 PM
#85
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08-30-2007, 02:29 PM
#86
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I recently switched(was forced to due to lack of Mobil 1 15W50) to a product called Liqui-Moly 10W60, well that is not the whole name but close enough. I notice much higher oil pressure at idle, even with the lower weight(at cold temp) 10 versus the 15 Mobil one. Pressure at highway cruising operation is around the same,I believe the 10W60 would hold up better at track conditions. Seems most companies are now producing/pushing a 10W60 product for road race cars.
08-30-2007, 02:48 PM
#87
Rennlist Member
08-31-2007, 08:25 AM
#88
Instructor
Am I missing something ?
The subject seems to be about hot oil pressure.
The "argument" seems to be about wether 0W or 5W is/was recommended or not.
I'm just an ignorant Structural injuneer but my simple understanding of the SAE classifications is that t'other number ie the bigger one is the one that dictates hot viscosity ie 30 or 40 or 50 generally (I note Penrite here in OZ produces oils up 70!).
Maybe someone can remind me what temperature the higher vicosity is measured at (I do recall that the lower number is a temperature not a viscosity). Is it possible that 928 oil temps at idle on a hot day in hotsville city arizona are hotter than the oil viscosity is measured at ? and further is it also possible that a true xxW/40 could actually retain that 40 viscosity at higher temperatures whereas a true xxW/50 could have a lower viscosity than the xxW/40 when subject to those temperatures ?
The subject seems to be about hot oil pressure.
The "argument" seems to be about wether 0W or 5W is/was recommended or not.
I'm just an ignorant Structural injuneer but my simple understanding of the SAE classifications is that t'other number ie the bigger one is the one that dictates hot viscosity ie 30 or 40 or 50 generally (I note Penrite here in OZ produces oils up 70!).
Maybe someone can remind me what temperature the higher vicosity is measured at (I do recall that the lower number is a temperature not a viscosity). Is it possible that 928 oil temps at idle on a hot day in hotsville city arizona are hotter than the oil viscosity is measured at ? and further is it also possible that a true xxW/40 could actually retain that 40 viscosity at higher temperatures whereas a true xxW/50 could have a lower viscosity than the xxW/40 when subject to those temperatures ?
The SAE (Society of Automotive Engineers) hot ("summer"?) viscosity grade is determined by the oil's kinematic viscosity at 100C (212F). To be graded SAE30 (ie xxW-30), the oil must be in the range 9.3-12.5 CSt at 100C; SAE40 12.5-16.3 CSt; SAE 50 16.3-21.9 CSt.
The SAE "winter", or Low Temperature Cranking, grade is determined by the oil having an absolute viscosity of less than a threshold at a specified temperature. These grading breaks have changed over the years but currently (since 1999, I think) are:
0W: <6200 cP @-35C (-31F)
5W: <6600 cP @-30C (-22F)
10W: <7000 cP @ -25C (-13F)
15W: <7000 cP @ -20C (-4F)
20W: <9500 cP @ -15C (5F)
25W: <13000 cP @ -10C (14F)
Although http://www.synlube.com/viscosit.htm is on a product website, it gives a good explanation of viscosity and SAE grades.
Another standard property specified for automotive engine oils is High Temperature High Shear ie the absolute viscosity at 150C (302F). An oil must meet the requirements of the European ACEA specification A3 (among other things) to gain Porsche approval. This requires the HTHS to be 3.5 cP or greater. While the HTHS is not publicised by all oil companies, if the oil is stated to comply with ACEA A3, you know that its HTHS is 3.5 cP or more.
As a result of the long-running debate on the landshark list, I have accumulated the publicised properties of 52 different oils graded xxW-40 or more, with some xxW-30s as well.
To answer your question whether an xxW-40 oil can have a higher viscosity than an xxW-50 at "higher temperatures" (ie greater than 100C): yes.
Of the seven xxW-40 oils in my list for which the HTHS is publicised, Redline 10W-40 (4.7 cP) and Redline 5W-40 (4.6 cP) have HTHSs higher than two of the eight xxW-50 oils for which I have the HTHS (Mobil 1 5W-50 (4.2 cP) and Penrite HPR10 10W-50 - an Australian-produced semi-synthetic (4.4 cP)).
10-28-2007, 09:16 AM
#89
Rennlist Member
Hmm, let's see racers and mechanics passing on their experience for free v's someone who espouses corporate adverjingle. I know which oil I would choose.
In fact the more you think about it why do these guys bother? Especially the mechanics who profit from the cars with problems rather than those that continue to run with just scheduled services. So be damned by all the jargon that the non-profit making oil companies spew out. Continue to use the Mobil 1's of this world, keep the small local mechanics in a job, and the big oil boys smiling. See, now who said there was a problem? Everyone's happy.
In fact the more you think about it why do these guys bother? Especially the mechanics who profit from the cars with problems rather than those that continue to run with just scheduled services. So be damned by all the jargon that the non-profit making oil companies spew out. Continue to use the Mobil 1's of this world, keep the small local mechanics in a job, and the big oil boys smiling. See, now who said there was a problem? Everyone's happy.
Last edited by 333pg333; 10-28-2007 at 10:38 AM.