Mobil 1 synthetic 15w-50 $4.74 qt
03-16-2007, 01:04 AM
#76
Burning Brakes
Join Date: Dec 2002
Location: Airlie Beach, Australia
Posts: 870
Likes: 0
Received 0 Likes
on
0 Posts
Hi,
James-man, you don't give details of the oil you currently use. It would be helpful to know this and when you get 4.5bar OP - for instance, is this at idle?
Constantine - sorry to hear about your engine failure. As most od us "know" these types of failures are usually caused by oil starvation
John V - yes, the 10w-60 goes from strength to strength and formulation to formulation.
At least BP didn't kill it with Brand engineering. It was a "full" ester oil when first released in the 1970s and the exhaust's smell was pure Castrol "R" - I'm real sorry it lost that!!
Rick (1) - The MC formulations are especially designed to handle integrated engine/gearboxes. BMC's Austin 850/Morris MINI was the car equivalent and a special lubricant and viscosity (20w-50) was formulated by Duckhams for that application. The problem primarily was/is permanent shearing of the lubricant which quickly reduces the oil's viscosity
I would not be using these viscosity lubricants in my 928!
I have included below some selected information that I posted within the last three weeks or so in the 993/966 Forums;
STARTS:
Oil Formulations
It is extremely unwise to concentrate on certain aspects of an engine lubricant's formulation. It is true that too little or too much of some "elements" in an oil's formulation is counterproductive both from a wear and durability viewpoint
Steve - There are some anomalies in the "Navarro"paper and this is to be expected in such things. One glaring anomaly is in categorising of Delvac 1 5w-40 as a mineral oil. It is actually one of the best oil formulations ever made - it is a Group 4/5 synthetic with a significant Ester content. Another is classing Castrol's Syntec 5w-50 as a synthetic - it can be called that in NA but it is actually a semi-synthetic. There are a number of other anomalies in the paper
Perhaps instead of concentrating on some "old" oil formulation items a study that embraced engine oil operating temperatures as a possible cause of "excessive" wear may well have been productive. Many people endeavour to run their engine/oil too cold! Oil performs best above 90C and up to 120C depending on its structure (Mineral/Synthetic).
Running the engine's oil in a core temperature band of from around 92C -110C is most desirable. Too cold will inhibit the action of some Anti Wear (AW) chemicals and will eventually be destructive to the engine/oil's condition
Using Used Oil Analysis (UOA)
UOAs are a great tool for determining an oil's condition. In the hands of a well practiced person a UOA may well pin point abnormal component wear or other issues such as intake system leaks or some cooling system issues
UOAs are NOT a suitable device to compare one Brand of oil against another in regard to engine wear rates. They are an excellent maintenance "tool" when used within engine families but will NOT predict a sudden failure. They may well alert a smart person to a potential for failure
They can tell how an oil performs within an engine (loss/gain in viscosity etc) and in a number of other critical matters such as the lubricant's ability to control acidity.
They are a great tool in determining when an oil change is required
Comparing wear metal rates in a 911 engine will mostly be an individual engine thing. This is called "trend analysis". Once additional oil coolers and other standard specification items are changed the metallurgical mix makes direct engine comparisons unreliable
Engine wear rates today are measured in "real time" by Radioactive Tracer Technology and etc. and is measured in nanometres (one millionth of a millimetre) per hour etc in clinical conditions with known technology within the engine. Some of these radionucleide tests run for 1000 hours or so and many are engine component specific (cams, rings etc). On road (user) testing still plays a very valuable role and extends for many millions of kms and sometimes for years
Supplementary Additives
The use of supplementary additives in engine oils was discussed in an earlier thread. IMHO it is unwise to add any supplementary additives to a modern engine lubricant - the risk of additive clash and other side affects is very real. That is the also the opinion of almost every Engine manufacturer and Lubricant producer
ENDS
Blending modern engine lubricants is a very complex science due to new and much better chemicals being made available. This is why I am a great believer in using the lubricants Approved by Porsche
Should you wish to have more information on this issue please search in the other Forms
Tony - your experience with oil temperatures roughly mirrors mine (via an IR reader). Typically from a cold start the oil's temp will trail the coolant by up to 20C when the coolant's thermostat is at "crack" point
Bill - I will shortly send you Private Message that compares a few SAE40 lubricants (0w-40, 5w-40) as their overall performance will all be somewhat different
I believe that some people have replaced the oil thermostat when low OP occured in an otherwise healthy engine - with great results
In bridging for a digital OP reading compared to the gauge some people have found the OP to be about 0.5 to 1bar higher than indicated on the gauge
Rick (2) - It is wise to remember that for 1992 all 928s had a factory fill of Shell TMO 5w-40 fully synthetic oil! (Initially in MY91 it was a semi synthetic, Shell TMO 10w-30)
At each stage from many years earlier the standard OP check was 5bar @ 4000rpm (some early MY @ 5000rpm)with the oil at >80C
An oil pump modification to earlier cars was made to enable better OP at hot idle
Regards
James-man, you don't give details of the oil you currently use. It would be helpful to know this and when you get 4.5bar OP - for instance, is this at idle?
Constantine - sorry to hear about your engine failure. As most od us "know" these types of failures are usually caused by oil starvation
John V - yes, the 10w-60 goes from strength to strength and formulation to formulation.
At least BP didn't kill it with Brand engineering. It was a "full" ester oil when first released in the 1970s and the exhaust's smell was pure Castrol "R" - I'm real sorry it lost that!!
Rick (1) - The MC formulations are especially designed to handle integrated engine/gearboxes. BMC's Austin 850/Morris MINI was the car equivalent and a special lubricant and viscosity (20w-50) was formulated by Duckhams for that application. The problem primarily was/is permanent shearing of the lubricant which quickly reduces the oil's viscosity
I would not be using these viscosity lubricants in my 928!
I have included below some selected information that I posted within the last three weeks or so in the 993/966 Forums;
STARTS:
Oil Formulations
It is extremely unwise to concentrate on certain aspects of an engine lubricant's formulation. It is true that too little or too much of some "elements" in an oil's formulation is counterproductive both from a wear and durability viewpoint
Steve - There are some anomalies in the "Navarro"paper and this is to be expected in such things. One glaring anomaly is in categorising of Delvac 1 5w-40 as a mineral oil. It is actually one of the best oil formulations ever made - it is a Group 4/5 synthetic with a significant Ester content. Another is classing Castrol's Syntec 5w-50 as a synthetic - it can be called that in NA but it is actually a semi-synthetic. There are a number of other anomalies in the paper
Perhaps instead of concentrating on some "old" oil formulation items a study that embraced engine oil operating temperatures as a possible cause of "excessive" wear may well have been productive. Many people endeavour to run their engine/oil too cold! Oil performs best above 90C and up to 120C depending on its structure (Mineral/Synthetic).
Running the engine's oil in a core temperature band of from around 92C -110C is most desirable. Too cold will inhibit the action of some Anti Wear (AW) chemicals and will eventually be destructive to the engine/oil's condition
Using Used Oil Analysis (UOA)
UOAs are a great tool for determining an oil's condition. In the hands of a well practiced person a UOA may well pin point abnormal component wear or other issues such as intake system leaks or some cooling system issues
UOAs are NOT a suitable device to compare one Brand of oil against another in regard to engine wear rates. They are an excellent maintenance "tool" when used within engine families but will NOT predict a sudden failure. They may well alert a smart person to a potential for failure
They can tell how an oil performs within an engine (loss/gain in viscosity etc) and in a number of other critical matters such as the lubricant's ability to control acidity.
They are a great tool in determining when an oil change is required
Comparing wear metal rates in a 911 engine will mostly be an individual engine thing. This is called "trend analysis". Once additional oil coolers and other standard specification items are changed the metallurgical mix makes direct engine comparisons unreliable
Engine wear rates today are measured in "real time" by Radioactive Tracer Technology and etc. and is measured in nanometres (one millionth of a millimetre) per hour etc in clinical conditions with known technology within the engine. Some of these radionucleide tests run for 1000 hours or so and many are engine component specific (cams, rings etc). On road (user) testing still plays a very valuable role and extends for many millions of kms and sometimes for years
Supplementary Additives
The use of supplementary additives in engine oils was discussed in an earlier thread. IMHO it is unwise to add any supplementary additives to a modern engine lubricant - the risk of additive clash and other side affects is very real. That is the also the opinion of almost every Engine manufacturer and Lubricant producer
ENDS
Blending modern engine lubricants is a very complex science due to new and much better chemicals being made available. This is why I am a great believer in using the lubricants Approved by Porsche
Should you wish to have more information on this issue please search in the other Forms
Tony - your experience with oil temperatures roughly mirrors mine (via an IR reader). Typically from a cold start the oil's temp will trail the coolant by up to 20C when the coolant's thermostat is at "crack" point
Bill - I will shortly send you Private Message that compares a few SAE40 lubricants (0w-40, 5w-40) as their overall performance will all be somewhat different
I believe that some people have replaced the oil thermostat when low OP occured in an otherwise healthy engine - with great results
In bridging for a digital OP reading compared to the gauge some people have found the OP to be about 0.5 to 1bar higher than indicated on the gauge
Rick (2) - It is wise to remember that for 1992 all 928s had a factory fill of Shell TMO 5w-40 fully synthetic oil! (Initially in MY91 it was a semi synthetic, Shell TMO 10w-30)
At each stage from many years earlier the standard OP check was 5bar @ 4000rpm (some early MY @ 5000rpm)with the oil at >80C
An oil pump modification to earlier cars was made to enable better OP at hot idle
Regards
03-16-2007, 02:33 AM
#77
Under the Lift
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Doug:
Thanks for the PM. Maybe I will give one of the good Xw-40s another try, although Castrol Syntec, on the good list, is one that would not maintain pressure at very high temps at idle. I already have the lower T-stat. That has essentially no effect on end-race temps as once the t-stat opens (or closes as is the case in our cars) it stays that way and the cooling system is capacity limited.
I'm concerned about the reported recent formulation change in M1 15W-50, greatly reducing Zn, boron and other anti wear elements. That's why I was asking about the Castrol 10W-60. I still think I need a 50W hot oil if Castrol Syntec 5W-40 isn't going to mainatin hot idle pressure for me at the races. I wondered if 10W-60 would make such a great racing oil, could I run it all the time.
Thanks for the PM. Maybe I will give one of the good Xw-40s another try, although Castrol Syntec, on the good list, is one that would not maintain pressure at very high temps at idle. I already have the lower T-stat. That has essentially no effect on end-race temps as once the t-stat opens (or closes as is the case in our cars) it stays that way and the cooling system is capacity limited.
I'm concerned about the reported recent formulation change in M1 15W-50, greatly reducing Zn, boron and other anti wear elements. That's why I was asking about the Castrol 10W-60. I still think I need a 50W hot oil if Castrol Syntec 5W-40 isn't going to mainatin hot idle pressure for me at the races. I wondered if 10W-60 would make such a great racing oil, could I run it all the time.
03-16-2007, 03:18 AM
#78
Burning Brakes
Join Date: Dec 2002
Location: Airlie Beach, Australia
Posts: 870
Likes: 0
Received 0 Likes
on
0 Posts
Hi Bill,
Delvac 1 and Rotella T synthetic are worth a try - both are very robust at higher temperatures!
In the order of the PM these figures apply to Castrol 10w-60;
-42C, 170, [39] [35] [29], 24.1, [18.5], 5.2
Castrol's 10w-60 is a very viscous lubricant even at high temperatures and you WILL show greater OP if that is what you really want. Its Pour Point of -42C is amazing really and an indicator of its structure
Castrol in OZ recommend it for a 928 used in competition
It would not be my choice for everyday use
As far as the formulation changes go, a lubricant must be seen as a chemical "cocktail" and I believe the new chemicals in consort with the reduced levels of others and more advanced base fluids will exceed expectations. Always ensure the any petrol engine lubricant for a 928 has ACEA A3/B3 on the label if it is not on the Approved List
HDEOs will not always have this!
Regards
Delvac 1 and Rotella T synthetic are worth a try - both are very robust at higher temperatures!
In the order of the PM these figures apply to Castrol 10w-60;
-42C, 170, [39] [35] [29], 24.1, [18.5], 5.2
Castrol's 10w-60 is a very viscous lubricant even at high temperatures and you WILL show greater OP if that is what you really want. Its Pour Point of -42C is amazing really and an indicator of its structure
Castrol in OZ recommend it for a 928 used in competition
It would not be my choice for everyday use
As far as the formulation changes go, a lubricant must be seen as a chemical "cocktail" and I believe the new chemicals in consort with the reduced levels of others and more advanced base fluids will exceed expectations. Always ensure the any petrol engine lubricant for a 928 has ACEA A3/B3 on the label if it is not on the Approved List
HDEOs will not always have this!
Regards
03-16-2007, 02:36 PM
#80
Rennlist Member
Bill - I noticed some Mobil 0w-50 in Walmart last week, although I didn't have a chance to read the bottle and/or confirm if it was full Synth, since I was making a bee-line for other items...pretty sure it was 0w-50 though. Might be worth looking into and I may be by there today to check the specs as well.
Excellent information Doug !!!
Excellent information Doug !!!
03-16-2007, 03:29 PM
#81
Rennlist Member
Bill, why dont you try a oil change with Amzoil 20-50 and see what you see during the hot open road races. dont think that is really a test or a risk due to very little high g turns.
Mk
Mk
Originally Posted by Bill Ball
Doug:
Thanks for the PM. Maybe I will give one of the good Xw-40s another try, although Castrol Syntec, on the good list, is one that would not maintain pressure at very high temps at idle. I already have the lower T-stat. That has essentially no effect on end-race temps as once the t-stat opens (or closes as is the case in our cars) it stays that way and the cooling system is capacity limited.
I'm concerned about the reported recent formulation change in M1 15W-50, greatly reducing Zn, boron and other anti wear elements. That's why I was asking about the Castrol 10W-60. I still think I need a 50W hot oil if Castrol Syntec 5W-40 isn't going to mainatin hot idle pressure for me at the races. I wondered if 10W-60 would make such a great racing oil, could I run it all the time.
Thanks for the PM. Maybe I will give one of the good Xw-40s another try, although Castrol Syntec, on the good list, is one that would not maintain pressure at very high temps at idle. I already have the lower T-stat. That has essentially no effect on end-race temps as once the t-stat opens (or closes as is the case in our cars) it stays that way and the cooling system is capacity limited.
I'm concerned about the reported recent formulation change in M1 15W-50, greatly reducing Zn, boron and other anti wear elements. That's why I was asking about the Castrol 10W-60. I still think I need a 50W hot oil if Castrol Syntec 5W-40 isn't going to mainatin hot idle pressure for me at the races. I wondered if 10W-60 would make such a great racing oil, could I run it all the time.
03-16-2007, 03:39 PM
#82
Rennlist Member
Talk to Mark and see if he was noticing the oil pressure fluxuation.
i think (just a guess) that maybe there is something to be said for some type of film left on parts by some oils during starvation. I dont know. but , what i do know is that i run left hand turns at max G forces all the time at the tracks i run the best at . Laguna, sears' carrocel and thunderhill. Im not lally gaggin around either. keep in mind, im running 4seconds faster at sears point than mark anderson ran back in 1999 with his 6.5 liter 420hp monster on DOTs with Speedvision . (ie 1:52 vs my 1:47.9) i only mention this to show, in order to make this time, there has to be some "g" forces generated. the carrocel is a high speed, constant radus left, one of the most famous in racing. it lasts for over 5-6 seconds. Ive never noticed any variance in oil pressure down this turn.
I use amzoil 20/50 racing oil and has the entire racing life of the holbert car, and its predicessor, the 5 liter part euro. i have seen no issues with oil pressure, however, i did a test 6 years ago with mobil 1 and the pressure droppred dramatically during race conditions and high ambient temps.
I have no baffle, no accusump , but always make sure the level is correct and change the oil after every 3 weekends. cheap insurance if you ask me!
mk
by the way, 43min of racing at sebring, you mean total for the weekend or were you running the enduro too? usually, the races are 25-30 mins long.
i think (just a guess) that maybe there is something to be said for some type of film left on parts by some oils during starvation. I dont know. but , what i do know is that i run left hand turns at max G forces all the time at the tracks i run the best at . Laguna, sears' carrocel and thunderhill. Im not lally gaggin around either. keep in mind, im running 4seconds faster at sears point than mark anderson ran back in 1999 with his 6.5 liter 420hp monster on DOTs with Speedvision . (ie 1:52 vs my 1:47.9) i only mention this to show, in order to make this time, there has to be some "g" forces generated. the carrocel is a high speed, constant radus left, one of the most famous in racing. it lasts for over 5-6 seconds. Ive never noticed any variance in oil pressure down this turn.
I use amzoil 20/50 racing oil and has the entire racing life of the holbert car, and its predicessor, the 5 liter part euro. i have seen no issues with oil pressure, however, i did a test 6 years ago with mobil 1 and the pressure droppred dramatically during race conditions and high ambient temps.
I have no baffle, no accusump , but always make sure the level is correct and change the oil after every 3 weekends. cheap insurance if you ask me!
mk
by the way, 43min of racing at sebring, you mean total for the weekend or were you running the enduro too? usually, the races are 25-30 mins long.
Originally Posted by Constantine
Hi Mark,
My engine failure at Sebring (1986.5 928S, stock engine with 125K+miles, recently replaced con-rod bearings 2-3K miles ago, GTS baffled, accusumped, Mobil 1 15-50 oil) I do not believe was showing any low pressure indications before the engine let go. The car was being driven by Mark Anderson who was probably driving it faster/harder than ever in it's life. The engine let go on the last lap after about 43 minutes of racing and just after completing a very fast, high G, left hand turn (turn 1) that is often sited to be the very worst for optimizing the engine design's weak points for getting oil to the 2/6 con rod bearings.
I still have not investigated the reason for the failure just yet so cannot comment/confirm it really was the 2/6 rod bearings. I did however notice the accusump acting a bit sluggish in discharging the oil when tripping the switch before engine start ups which might have been a contributing factor. I am planning on sending the accusump to Canton to have them go through it.
Great oil discussion by the way,
Constantine
Mark K. Qoute:
"Most recently, the failure at Sebring, coupled with the low pressure indications, makes me very nervous about the performance of Mobil 1, for our cars, in high temp activities.
Mk"
My engine failure at Sebring (1986.5 928S, stock engine with 125K+miles, recently replaced con-rod bearings 2-3K miles ago, GTS baffled, accusumped, Mobil 1 15-50 oil) I do not believe was showing any low pressure indications before the engine let go. The car was being driven by Mark Anderson who was probably driving it faster/harder than ever in it's life. The engine let go on the last lap after about 43 minutes of racing and just after completing a very fast, high G, left hand turn (turn 1) that is often sited to be the very worst for optimizing the engine design's weak points for getting oil to the 2/6 con rod bearings.
I still have not investigated the reason for the failure just yet so cannot comment/confirm it really was the 2/6 rod bearings. I did however notice the accusump acting a bit sluggish in discharging the oil when tripping the switch before engine start ups which might have been a contributing factor. I am planning on sending the accusump to Canton to have them go through it.
Great oil discussion by the way,
Constantine
Mark K. Qoute:
"Most recently, the failure at Sebring, coupled with the low pressure indications, makes me very nervous about the performance of Mobil 1, for our cars, in high temp activities.
Mk"
03-16-2007, 06:33 PM
#83
Rennlist Member
Checked WallyWorld, the grade was 0w-40 European Car, not 0w-50. Full Synthetic (ACEA A3, B3/B4; API SM, SL/CF) - won't help the high end of 50w unfortunately...ahh well.
03-16-2007, 07:45 PM
#85
Burning Brakes
Join Date: Dec 2002
Location: Airlie Beach, Australia
Posts: 870
Likes: 0
Received 0 Likes
on
0 Posts
Hi,
Mark - this Thread has developed into a discussion on Racing Oils when the original intent was to simply cover M1 15w-50
Sadly the "test" of M1 15w-50 you did six years ago bears no relationship to the modern formulations!
There is no doubt that comparing your use of Amsoil to the likes of Castrol's "R"10w-60 is a chalk and cheese issue. The Castrol product has a very extensive history in motorsport over 30 years including winning in 1989 at LeMans, F1 successes, World Sports Car Championships and the like and is a much better product
Bill - the relevant data for the Amsoil product that Mark "promotes" is as follows;
-36, 128.1, [30] [26] [22], 18 [14], 5.1
To get back to the intent of this thread concerning M1 15w-50 and in IMHO;
1 - M1 15w-50 is not Porsche Approved but in warm climates it will do a "suitable" job.
In the absence of the Approved M1 5w-50 it is a robust oil satisfactorily used by many 928 owners in the USA as we all know
2 - A 5w-40 Approved lubricant is best for a 928 engine
3 - HOT (80C) oil pressure will NEED to be near these values
Early engine 5bar @ 5000rpm
Late engines 5bar @ 4000rpm
4 - Most 928s will show these values when using an approved lubricant
Idle (around 700rpm) >1.5bar (normally 2 to 3bar - and desirable)
1500 rpm near 4bar
2000rpm near 5bar
5 - In normal use and ambient (35C) the 928's oil temperature will rarely reach or exceed 100C for very long periods. In most cases when fully warmed up a 928's oil temperature will be around 93-95C and a SAE40 Approved oil at that point will have a viscosity near to or in the SAE50's viscosity range at 100C
6 - No SAE50 oils (except Mobil 1 5w-50) have been Porsche Approved for many years
7 - Using oils with a cold "W" rating above 5w (eg 10w,15w,20w and etc) will simply take proportionally longer to fully circulate through the lubrication system and to become fully filtered
8 - Extremely experience Factory Technical personnel always ensure an oil temperature of >80C is reached before "loading" the engine when using 20w-50 oils in "old" racing engines.
Refer to 2) 5) and 6) above
Mark - if you wish to start a Thread on Racing Oils for a 928 please do a search first
hupp - good one! - please keep us posted on your experience with Rotella T synthetic 5w-40
Regards
Mark - this Thread has developed into a discussion on Racing Oils when the original intent was to simply cover M1 15w-50
Sadly the "test" of M1 15w-50 you did six years ago bears no relationship to the modern formulations!
There is no doubt that comparing your use of Amsoil to the likes of Castrol's "R"10w-60 is a chalk and cheese issue. The Castrol product has a very extensive history in motorsport over 30 years including winning in 1989 at LeMans, F1 successes, World Sports Car Championships and the like and is a much better product
Bill - the relevant data for the Amsoil product that Mark "promotes" is as follows;
-36, 128.1, [30] [26] [22], 18 [14], 5.1
To get back to the intent of this thread concerning M1 15w-50 and in IMHO;
1 - M1 15w-50 is not Porsche Approved but in warm climates it will do a "suitable" job.
In the absence of the Approved M1 5w-50 it is a robust oil satisfactorily used by many 928 owners in the USA as we all know
2 - A 5w-40 Approved lubricant is best for a 928 engine
3 - HOT (80C) oil pressure will NEED to be near these values
Early engine 5bar @ 5000rpm
Late engines 5bar @ 4000rpm
4 - Most 928s will show these values when using an approved lubricant
Idle (around 700rpm) >1.5bar (normally 2 to 3bar - and desirable)
1500 rpm near 4bar
2000rpm near 5bar
5 - In normal use and ambient (35C) the 928's oil temperature will rarely reach or exceed 100C for very long periods. In most cases when fully warmed up a 928's oil temperature will be around 93-95C and a SAE40 Approved oil at that point will have a viscosity near to or in the SAE50's viscosity range at 100C
6 - No SAE50 oils (except Mobil 1 5w-50) have been Porsche Approved for many years
7 - Using oils with a cold "W" rating above 5w (eg 10w,15w,20w and etc) will simply take proportionally longer to fully circulate through the lubrication system and to become fully filtered
8 - Extremely experience Factory Technical personnel always ensure an oil temperature of >80C is reached before "loading" the engine when using 20w-50 oils in "old" racing engines.
Refer to 2) 5) and 6) above
Mark - if you wish to start a Thread on Racing Oils for a 928 please do a search first
hupp - good one! - please keep us posted on your experience with Rotella T synthetic 5w-40
Regards
03-17-2007, 06:09 AM
#86
Under the Lift
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Originally Posted by mark kibort
Bill, why dont you try a oil change with Amzoil 20-50 and see what you see during the hot open road races. dont think that is really a test or a risk due to very little high g turns.
Mk
Mk
03-17-2007, 08:55 AM
#87
Race Car
Originally Posted by Doug Hillary
Hi,
James-man, you don't give details of the oil you currently use. It would be helpful to know this and when you get 4.5bar OP - for instance, is this at idle?
James-man, you don't give details of the oil you currently use. It would be helpful to know this and when you get 4.5bar OP - for instance, is this at idle?
I usually do not look at the gauges until after executing a turn, so I have no real sense of what is going on in carousel turns. I do recall looking once mid-turn and not seeing anything of concern (probably pegged at 5, as usual). I am no Schumi and don't video the cockpit like many amateurs do. I can try to pay better attention to the oil guage next day out at the track.
I think I'd like to get back to using synthetic. Thanks.
03-17-2007, 09:13 AM
#88
Addict
Lifetime Rennlist
Member
Lifetime Rennlist
Member
I can try to pay better attention to the oil guage next day out at the track.
The stock 928 OP gauge doesn't react fast enough to see the dip that kills the 2/6.
The best thing is a data acquisition unit (I like Aim's Mychron3) and look at it after the session is over.
Bill, try the 10w-60. It's $$, but will work well for those high speed runs.
03-17-2007, 02:04 PM
#89
Burning Brakes
Join Date: Jul 2003
Location: IL
Posts: 1,166
Likes: 0
Received 0 Likes
on
0 Posts
All this oil talk is a bunch of sludged up boiling over from a few loose oil cans!
They are spewing out their breather vents to make an oil slick for happy running engines everywhere!
Then theres the old timers who drink oil and don't care what kind it is, they are the dirty old engines!
The new comers who get sucked into drinking snake oil when its more fun to blow dyno oil out their exhaust pipes like the old timers do!
Then theres the dyed in the wool types who's engine rings and seals get hardened by even looking at another brand of oil!
Its a hypocritical meltdown. A bunch of coked up turbo bearings talking sludge!
They are spewing out their breather vents to make an oil slick for happy running engines everywhere!
Then theres the old timers who drink oil and don't care what kind it is, they are the dirty old engines!
The new comers who get sucked into drinking snake oil when its more fun to blow dyno oil out their exhaust pipes like the old timers do!
Then theres the dyed in the wool types who's engine rings and seals get hardened by even looking at another brand of oil!
Its a hypocritical meltdown. A bunch of coked up turbo bearings talking sludge!
03-17-2007, 04:05 PM
#90
Instructor
Join Date: Jul 2002
Location: Sweden
Posts: 103
Likes: 0
Received 0 Likes
on
0 Posts
I'm running Castrol RS 10/60 in my 928 and it works great. With 5/40 the oil pressure was dropping after 10 minutes on the track to around 1 bar at 1500rpm. This was to low for my taste so I changed to Castrol. The oil pressure i now always above 2bar even after 20minutes on the track.
A good 20/50 oil is ok too but it's a bit to thick for my taste, too hard on the engine when cold.
Just my 5 cents in this oil discussion.
A good 20/50 oil is ok too but it's a bit to thick for my taste, too hard on the engine when cold.
Just my 5 cents in this oil discussion.