What motor oil do you use?
09-12-2003, 05:18 PM
#16
Rennlist Member
most all engine #2-6 bearing failures have been on mobil 1. Glad to see im not alone with my drastically lower oil presure with the mobil 1 on my 79 race car (now with a new owner who will change the oil and see if that problem goes away)
I use Amzoil 20-50, and it keeps the pressure up, and its wear tests against redline and mobile are significantly better.
As Don Hanson says, its Luck or the oil why my racing engines have not seen any failures over the last 102 race days!!!
MK
I use Amzoil 20-50, and it keeps the pressure up, and its wear tests against redline and mobile are significantly better.
As Don Hanson says, its Luck or the oil why my racing engines have not seen any failures over the last 102 race days!!!
MK
09-13-2003, 03:28 AM
#19
Burning Brakes
Join Date: Dec 2002
Location: Airlie Beach, Australia
Posts: 870
Likes: 0
Received 0 Likes
on
0 Posts
Hi,
for your interest, in October I will be able to produce "Oil Condition Report No 4" on here. This is the last Report in a year long project to validate the Porsche Handbook's recommended oil change period. It will have involved obtaining four used oil analysis reports of the 15w-50 Shell Helix Ultra synthetic oil in my car. I have paid ExxonMobil's laboratory to carry out the analysis to ensure impartiality
In general terms the last survey here on oils showed that owners who responded used an oil of 10w or 15w to 40 or 50 ( say 10w-40 ). These are amongst the grades recommended in the Handbook. The most popular oil was Mobil 1 - it is the Worlds best selling synthetic oil anyway. With some justification!
Synthetic or Mineral ?. Well honestly, for a low use vehicle the jury will always be out on this issue. Porsche have factory filled a special "factory fill blend" synthetic since 1992. I have used synthetic's for 30 odd years
You should NOT use any of the new low viscosity API SL 0w-20, 0w-30 etc. viscosity oils in your 928. These oils generally have a lower HT/HS - the ability to minimise "shear" at or above 150C - than the thicker viscosities. Some evidence is accruing to the argument that there may be a trade off sacrifice - more wear for better fuel economy
Any oil you do use should have "ACEA approval A3-96>,B3-96>" on the container's spec analysis along with "Porsche Approved" and preferably MB 229.1, MB 229.3. An API rating of SL> to SH is ok too, along with the others. These oils will meet the higher HT/HS ratings
There is a plethora of excellent oils available today - both mineral and synthetic. However, and against all arguments to the contrary there is no "magic elixer" oil !!! Believe me
I live in the complex world of Tribology and have done so for many years and I hope this little bit of info. helps
Regards
for your interest, in October I will be able to produce "Oil Condition Report No 4" on here. This is the last Report in a year long project to validate the Porsche Handbook's recommended oil change period. It will have involved obtaining four used oil analysis reports of the 15w-50 Shell Helix Ultra synthetic oil in my car. I have paid ExxonMobil's laboratory to carry out the analysis to ensure impartiality
In general terms the last survey here on oils showed that owners who responded used an oil of 10w or 15w to 40 or 50 ( say 10w-40 ). These are amongst the grades recommended in the Handbook. The most popular oil was Mobil 1 - it is the Worlds best selling synthetic oil anyway. With some justification!
Synthetic or Mineral ?. Well honestly, for a low use vehicle the jury will always be out on this issue. Porsche have factory filled a special "factory fill blend" synthetic since 1992. I have used synthetic's for 30 odd years
You should NOT use any of the new low viscosity API SL 0w-20, 0w-30 etc. viscosity oils in your 928. These oils generally have a lower HT/HS - the ability to minimise "shear" at or above 150C - than the thicker viscosities. Some evidence is accruing to the argument that there may be a trade off sacrifice - more wear for better fuel economy
Any oil you do use should have "ACEA approval A3-96>,B3-96>" on the container's spec analysis along with "Porsche Approved" and preferably MB 229.1, MB 229.3. An API rating of SL> to SH is ok too, along with the others. These oils will meet the higher HT/HS ratings
There is a plethora of excellent oils available today - both mineral and synthetic. However, and against all arguments to the contrary there is no "magic elixer" oil !!! Believe me
I live in the complex world of Tribology and have done so for many years and I hope this little bit of info. helps
Regards
09-13-2003, 03:49 AM
#20
Burning Brakes
Join Date: Dec 2002
Location: Airlie Beach, Australia
Posts: 870
Likes: 0
Received 0 Likes
on
0 Posts
Hi,
sorry fellas, in my earlier post here I forgot to include the madatory API diesel oil rating required for all 928 engine oils. This should be CI>CD, the ACEA rating is B3 which I included. Diesel ratings are mandatory for the 928 in order to prevent internal engine deposits - high temperature varnish and low temperature sludge. And, deposits in the ring and combustion chamber areas
This means that the rating on the container should look like this;
API SL>SH/CI>CD, ACEA A3-96>/B3-96> and etc.
Always use the correct viscosity recommended for your climate, short term temperature variances are allowed for in the recommendations
Regards
sorry fellas, in my earlier post here I forgot to include the madatory API diesel oil rating required for all 928 engine oils. This should be CI>CD, the ACEA rating is B3 which I included. Diesel ratings are mandatory for the 928 in order to prevent internal engine deposits - high temperature varnish and low temperature sludge. And, deposits in the ring and combustion chamber areas
This means that the rating on the container should look like this;
API SL>SH/CI>CD, ACEA A3-96>/B3-96> and etc.
Always use the correct viscosity recommended for your climate, short term temperature variances are allowed for in the recommendations
Regards
09-13-2003, 03:56 AM
#21
Cottage Industry Sponsor
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Just for curiosity, Doug, what is the cost of an oil analysis? Seems like you might be spending a lot of money on that research - or maybe saving a lot by proving Jiffy Lube's 3,000 mile chenge recommendation wrong.
09-13-2003, 06:17 AM
#22
Burning Brakes
Join Date: Dec 2002
Location: Airlie Beach, Australia
Posts: 870
Likes: 0
Received 0 Likes
on
0 Posts
Hi,
Nicole - the cost is $A50 per sample - money is of no consequence to me
Over the years I have taken hundreds of samples from my vehicles for used oil analysis ( UOA ) mainly on my heavy truck engines, diffs and gearboxes. I have done this type of thing since about 1980. Ii is a matter of cost/benefit - a commercial decision. This UOAs programme has been undertaken to establish the optimum oil change intervals and to track engine wear trends. At 38ltrs ($A400) and $A120 ( filters ) per OC it is worthwhile
Now, On I change Mobil Delvac 1 5w-40 synthetic oil at 100kkms intervals with these vehicles. This has been established via UOAs and in consort with the Oil Company and Detroit Diesel the engine maker. Some of these engines have had over 1million kms recorded. I use a Mann-Hummel oil centrifuge on each engine too as a result of the UOAs. These collect mainly soot from the oil
The UOA on my 928 happened after an exchange on this List in February '03 when my competency in this area ( and methodology ) along with my technical knowledge was challenged. It seemed fair to take on the challenge and to wear the costs! I made the offer - and carried it through
A search sort here will find the "exchange" and the comments made by Mark@DEVEK and some others who no longer seem to post here very often
I have nothing to prove, I offered to share the results and this is what I have done. In some detail too as you have remarked on before
I have the utmost faith in the competency, knowledge and integrity of the Porsche personnel who originally made the oils' recommendations and the oil change recommendations contained in the Owners Handbook. And in the Workshop Manuals too
I see that you are an annual/distance changer of oils too, as per the Handbook - a mark of confidence and experience.
And as Jim Bailey and Wally Plumley said at the time - its common sense!
Regards
Nicole - the cost is $A50 per sample - money is of no consequence to me
Over the years I have taken hundreds of samples from my vehicles for used oil analysis ( UOA ) mainly on my heavy truck engines, diffs and gearboxes. I have done this type of thing since about 1980. Ii is a matter of cost/benefit - a commercial decision. This UOAs programme has been undertaken to establish the optimum oil change intervals and to track engine wear trends. At 38ltrs ($A400) and $A120 ( filters ) per OC it is worthwhile
Now, On I change Mobil Delvac 1 5w-40 synthetic oil at 100kkms intervals with these vehicles. This has been established via UOAs and in consort with the Oil Company and Detroit Diesel the engine maker. Some of these engines have had over 1million kms recorded. I use a Mann-Hummel oil centrifuge on each engine too as a result of the UOAs. These collect mainly soot from the oil
The UOA on my 928 happened after an exchange on this List in February '03 when my competency in this area ( and methodology ) along with my technical knowledge was challenged. It seemed fair to take on the challenge and to wear the costs! I made the offer - and carried it through
A search sort here will find the "exchange" and the comments made by Mark@DEVEK and some others who no longer seem to post here very often
I have nothing to prove, I offered to share the results and this is what I have done. In some detail too as you have remarked on before
I have the utmost faith in the competency, knowledge and integrity of the Porsche personnel who originally made the oils' recommendations and the oil change recommendations contained in the Owners Handbook. And in the Workshop Manuals too
I see that you are an annual/distance changer of oils too, as per the Handbook - a mark of confidence and experience.
And as Jim Bailey and Wally Plumley said at the time - its common sense!
Regards
