Which oil provides the best protection? You might be surprised to find out...
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Originally Posted by Joe Weinstein
Hi. Pressure is important for flow, but pressure is not what keeps
parts from touching. That is film strength/shear resistence, which
does relate to viscosity, but the oil has to be thin enough to get
into the gap to begin with, and has to be flowing through fast enough
to carry heat away, and not stay there and get cooked. Pressure
itself is never used to lift parts. Typically a bearing has oil pressure
all around the shaft, not just in one place liting it off the bearing
surface, so the pressure cancels itself all around. You want a thick-
enough oil, but no thicker, and flowing fast enough to stay cool
under pressure at peak engine loads so parts don't expand because
of heat and cause interferance contact. Friction = heat. Viscosity =
liquid friction.
Yep. That's why we hear about so many Porsche motors failing.
What you want is an oil that gets to the dry parts as fast as possible
at startup. That's why the "0-" part is so important. If your motor
has such loose tolerances that a hiccup means a lot of banging
around in the bearing races, then gear-case oils would be better.
We disagree on les drag equalling less protection. Why not try
a 90-wt? What are you referring to regarding good-for-seal/bad-for-seal?
It's anecdotal, but I have one of the first 996tts in the country (August
2000) and have used my car harder than most everyone on this list, I'll
bet. I take complete notes. Since purchase, I have averaged 8 mpg!
I have used 1 qt of mobil-1 per 1000 miles, and almost all of them have
been in competition.
As you wish. It all depends on who you trust, and what you actually
do with the car. For most people, oil is like underwear, Gucci or Target,
it's more to do with how often you change.
Post to the RennList race
group about how many still use thin untrustworthy Mobil-1, and about all
their inexplicable lack of oil-related failures.
Joe
parts from touching. That is film strength/shear resistence, which
does relate to viscosity, but the oil has to be thin enough to get
into the gap to begin with, and has to be flowing through fast enough
to carry heat away, and not stay there and get cooked. Pressure
itself is never used to lift parts. Typically a bearing has oil pressure
all around the shaft, not just in one place liting it off the bearing
surface, so the pressure cancels itself all around. You want a thick-
enough oil, but no thicker, and flowing fast enough to stay cool
under pressure at peak engine loads so parts don't expand because
of heat and cause interferance contact. Friction = heat. Viscosity =
liquid friction.
Yep. That's why we hear about so many Porsche motors failing.
What you want is an oil that gets to the dry parts as fast as possible
at startup. That's why the "0-" part is so important. If your motor
has such loose tolerances that a hiccup means a lot of banging
around in the bearing races, then gear-case oils would be better.
We disagree on les drag equalling less protection. Why not try
a 90-wt? What are you referring to regarding good-for-seal/bad-for-seal?
It's anecdotal, but I have one of the first 996tts in the country (August
2000) and have used my car harder than most everyone on this list, I'll
bet. I take complete notes. Since purchase, I have averaged 8 mpg!
I have used 1 qt of mobil-1 per 1000 miles, and almost all of them have
been in competition.
As you wish. It all depends on who you trust, and what you actually
do with the car. For most people, oil is like underwear, Gucci or Target,
it's more to do with how often you change.
Post to the RennList racegroup about how many still use thin untrustworthy Mobil-1, and about all
their inexplicable lack of oil-related failures.
Joe
First off, we are talking about a car used for street and occasional track. Obviously, if your car if for competition only, you want to tweak out every bit of power you can from the engine, which would include having less drag caused by the oil.
We will have to agree to disagree. Pressure does in fact play a very important and REQUIRED part in keeping parts alligned and seperated. Without enough pressure, parts would not operate concentrically. Film strength is directly related to pressure.
Additionally, oil flow and/or lack of lubriction being the biggest cause of engine wear at startup has been a myth that most people have come to accept as fact. By far, the greatest contributer to startup wear is condensation cause by incomplete combustion on a cold engine. It doesn't matter whether you have 0W or 100W oil in the crankcase, you will have condensation in your engine on cold start.
I'll look for the most recent study, but I think the study contributed inssufficient oil to only 15% of startup engine wear.
As far as seals go, it is not the weight causing the seal to leak, but the lack of conditioners in some synthetics that can cause thin oil to pass by the ever shrinking material.
As with most other things, there are always variables and exceptions. Like I mentioned earlier: this guy I know ran a Dodge engine for 150,000 miles with the same oil, no problems. Would most cars be able to do that? Unlikely and I don't think many would want to test it.
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There's your conspiracy theory. You're welcome to it. If longevity
is the criterion instead of hight-stress protection, then it is the
additives that protect against oxidation, and the quick-flowing
at startup that should matter, and we are still all waiting for the
first controlled long-term test that shows any increased motor
life from thicker/different oils. Let's take a poll on hoe many folks
bought their last Porsche because their first one just wore out?
Joe
is the criterion instead of hight-stress protection, then it is the
additives that protect against oxidation, and the quick-flowing
at startup that should matter, and we are still all waiting for the
first controlled long-term test that shows any increased motor
life from thicker/different oils. Let's take a poll on hoe many folks
bought their last Porsche because their first one just wore out?
Joe
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From: Chicagoland
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Originally Posted by jimmer23
Last time I checked, Porsche made money from selling more cars, not recommending the best oil. 
There is such a thing as built-in obsolescence, or a finite lifespan for that matter. If all Porsche engines, bodies, trannys, etc etc etc lasted 500k miles, they'd be broke. It's like the lightbulb that lasts for 20 years - it can be done, but why would anyone produce it? I'm sure Mobil-1 or whatever they recommend is good enough to give a long enough lifespan to make clients just happy enough to shell out bucks for their next $100k+ car. Ignorance is bliss...
There is such a thing as built-in obsolescence, or a finite lifespan for that matter. If all Porsche engines, bodies, trannys, etc etc etc lasted 500k miles, they'd be broke. It's like the lightbulb that lasts for 20 years - it can be done, but why would anyone produce it? I'm sure Mobil-1 or whatever they recommend is good enough to give a long enough lifespan to make clients just happy enough to shell out bucks for their next $100k+ car. Ignorance is bliss... A perfect example of this is Norelco electric shavers. In the 80's they had a razor with self sharpening blades. I still have one and it still works fine. Nowadays, the blades need replacing when they are dull.
HP almost gives printers away, but you need a mortgage to buy their half full ink cartridges.
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Originally Posted by 1999Porsche911
First off, we are talking about a car used for street and occasional track. Obviously, if your car if for competition only, you want to tweak out every bit of power you can from the engine, which would include having less drag caused by the oil.
We will have to agree to disagree.
We will have to agree to disagree.
is good for follow-ups for anyone that wants
to try out their ideas and theories:
http://www.bobistheoilguy.com/
And my car is regularly driven hours and back to the events,
and has 13,000 miles on it (I know, only driven on weekends
)without being opened up. That's 13,000 miles *at 8 MPG*.
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Originally Posted by Joe Weinstein
It's anecdotal, but I have one of the first 996tts in the country (August
2000)....
2000)....
Totally O/T...but when were the first 996TT's sold in the US? I only ask because my car was sold to the original owner July 15th, 2000 in Pompano Beach, FL.
Can I assume my car is a very early one?
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Originally Posted by Joe Weinstein
PorschePHD has said
that his rebuilt engines burn much less oil than stock motors.
that his rebuilt engines burn much less oil than stock motors.
https://www.6speedonline.com/forums/...oil#post589095
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Whomever thinks oil consumption is ok, needs to go back and re-evaluate exactly what burning oil does to a motor, especially a turbocharged one. The fact that it destroys the octane rating of the fuel is just a minor issue in the long run.
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Hi Scott, yes, your's is an early one. Vicious, it is good
but complex to know what causes oil consumption. It
is not always burning, it can be simple evaporation of
the volatile components of the oil, which may be planned,
to keep the oil viscosity stable and compensate for thinning
due to wear. Better info will come from that oil site, but
I would think that the degree that it was burned,
eg: 13,000 miles @ 8mpg = 1,625 gallons of gas,
burning 13 qts of oil ->
99.8% gasoline + 0.2% oil
coupled with the fact that oil is *less* volatile than
gasoline, if it had *any* effect, it would decrease
the possibility of knocking, so it would not hurt
the octane rating.
but complex to know what causes oil consumption. It
is not always burning, it can be simple evaporation of
the volatile components of the oil, which may be planned,
to keep the oil viscosity stable and compensate for thinning
due to wear. Better info will come from that oil site, but
I would think that the degree that it was burned,
eg: 13,000 miles @ 8mpg = 1,625 gallons of gas,
burning 13 qts of oil ->
99.8% gasoline + 0.2% oil
coupled with the fact that oil is *less* volatile than
gasoline, if it had *any* effect, it would decrease
the possibility of knocking, so it would not hurt
the octane rating.
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Originally Posted by Joe Weinstein
coupled with the fact that oil is *less* volatile than
gasoline, if it had *any* effect, it would decrease
the possibility of knocking, so it would not hurt
the octane rating.
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No, the mix of hydrocarbons they use to calibrate octane
ratings is a mixture of octane and heptane. The lighter
heptane is what causes detonation. More volatile means
more likely to explode as opposed to burn. Diesel fuel is *oil*,
which is why it can be burned so safely at such high compression
ratios with no detonation.
As to film strength relating to oil pressure, RedLine thinks
not:
"If clearances are tight and very little lugging occurs,
then the 5W30 or 10W30 should be adequate. Less
turbo lag will be noticed with the 5W30. If ambient
temperatures will regularly climb above 100°F, then
the 10W40 would provide an additional safety margin.
If the engine is air-cooled, or if the engine is older and
has greater bearing and ring clearances, the 15W50
and 20W50 will develop a thicker oil film. If very low
temperatures occur, the lower viscosity grades,
(5W30, 10W30, or 10W40) will flow better and
lubricate the engine more quickly after start-up."
ratings is a mixture of octane and heptane. The lighter
heptane is what causes detonation. More volatile means
more likely to explode as opposed to burn. Diesel fuel is *oil*,
which is why it can be burned so safely at such high compression
ratios with no detonation.
As to film strength relating to oil pressure, RedLine thinks
not:
"If clearances are tight and very little lugging occurs,
then the 5W30 or 10W30 should be adequate. Less
turbo lag will be noticed with the 5W30. If ambient
temperatures will regularly climb above 100°F, then
the 10W40 would provide an additional safety margin.
If the engine is air-cooled, or if the engine is older and
has greater bearing and ring clearances, the 15W50
and 20W50 will develop a thicker oil film. If very low
temperatures occur, the lower viscosity grades,
(5W30, 10W30, or 10W40) will flow better and
lubricate the engine more quickly after start-up."
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I wholeheartedly agree with Joe Weinstein.
But for the record, on my Turbocharged Integra Type-R, I was burning Mobil 1 5w-30 big time and when I switched to Amsoil 5w-30, I burned almost nothing.
That being said, I will ONLY use Mobil 1 in my Porsche anyway.
If ANYTHING goes wrong with the engine, I don't want the dealer to have ANY EXCUSE WHATSOEVER that the oil I used was at fault.
- KJ
But for the record, on my Turbocharged Integra Type-R, I was burning Mobil 1 5w-30 big time and when I switched to Amsoil 5w-30, I burned almost nothing.
That being said, I will ONLY use Mobil 1 in my Porsche anyway.
If ANYTHING goes wrong with the engine, I don't want the dealer to have ANY EXCUSE WHATSOEVER that the oil I used was at fault.
- KJ
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Just curious, for those of you who use Amsoil which product do you use? There are many? Also, is your engine stock other than maybe a stage 1-4 upgrade?
This is very interesting reading.
Thanks,
Adam
This is very interesting reading.
Thanks,
Adam
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From: Toronto
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Also, I might add that a lot of those old-school "Teflon Oil Additives" they used to sell on TV like Duralube, Slick 50 etc. would lead to NO damage whatsoever on the bearing in this exact same test (when added to conventional oil). That being said, NO ONE in their right mind would put Dura Lube or Slick 50 in their cars now!!!
- KJ
- KJ
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Originally Posted by KJM3
That being said, I will ONLY use Mobil 1 in my Porsche anyway.
If ANYTHING goes wrong with the engine, I don't want the dealer to have ANY EXCUSE WHATSOEVER that the oil I used was at fault.
- KJ
If ANYTHING goes wrong with the engine, I don't want the dealer to have ANY EXCUSE WHATSOEVER that the oil I used was at fault.
- KJ
Last edited by Divexxtreme; Apr 4, 2007 at 05:26 PM.
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Originally Posted by alevine
Just curious, for those of you who use Amsoil which product do you use? There are many? Also, is your engine stock other than maybe a stage 1-4 upgrade?
This is very interesting reading.
Thanks,
Adam
This is very interesting reading.
Thanks,
Adam
