Joe,

Out of curiosity, I contacted the VIN expert over on Renntech.org, and apparently, my car is #469 built for the US. Interesting.

 

Thanks, and you may be entirely accurate. The Amsoil 5w-30
may be significantly thicker that the Modil-1 5w-30. And at
the levels that Porsche says are normal, 1 qt/1000 miles,
no one has established any real jeopardy in the burning of
oil, and there may well be a beneficial tradeoff in the increased
speed of flow of the thinner 5w-30, as long as you believe
Porsche thinks it's still stable and thick enough for keeping a
motor healthy.
Joe

 

Another informative/interesting thread and debate... Scott or anyone, when i go for my oil change, what should i change too?

 

You're going to get a ton of opinions on this one, bro.

What would I do if I were you? I'd use the oil RUF recommends. Unless it's Mobile-1, that is.

 

GOOD advice Scott PM brotha

 

If you're suspicious about Mobil-1, I would recommend RedLine Oil.
In the last long-term broad oil test I still have, done by Motorcycle
Consumer News, about 50 oils were tested and analysed for the
four major performance criteria:

* TBN (total base numbers): This is the amount of antioxidants, acid
neutralizers. Acid comes about when oil is contaminated by partial
combustion byproducts, and water from condensation, especially
if driven short distances only, where the oil doesn't get and stay
hot enough to boil off the water. If your oil's additives get used
up, the forther acid production will eat your motor from the
inside.
* Lubricity additives (zinc,phosphorus, molybdenum). These will
adhere to metal and provide protection during startup before
fresh oil gets pumped to the area.
* Evaporative stability. This is a measure of the uniformity of the
oil base. Dyno oil is a natural product, and has a lot of different-
length polymer chains, the shorter of which can evaporate away,
even with a zero-oil-burning engine, the oil volume can drop if
enough of the oil can evaoprate away. Synthetics are chemically
creatd, and typically do much better in this regard. In fact, some
viscosity recommendations ask for a bit more thickness in order
to allow for a safety factor for the variability of 'dino-oil'. A good
synthetic with a more reliable/uniform viscosity can often serve
and protect equally at a lighter viscosity because it's not going to
be any lighter than it's spec.
* Viscosity stability. This is hard to measure in a controlled way,
because it relates to the previous criterion, and to how much
the oil gets diluted by gasoline blowing past the rings, etc, but
it's value is clear. You don't want an oil that gets thinner or
thicker with use.

You already know I trust Mobil-1, and it is partially based on these
test results. The one oil brand that was always in the top for all
categories was RedLine.

There's another issue nowadays, that may favor thicker oils. For
emmissions/polution reasons, the oil manufacturers are being forced
to lower some of the beneficial zinc in the automobile oils, but they
are still able to put the best additives in their thicker truck and
motorcycle oils. One tactic you can use, is to make use of the fact
that viscosity is not linear, it is logarithmic. That means that unlike
octane, if you mix 50% of one viscosity with 50% of another, you
don't get the numerical average. You get very close to the thinner
of the two oils. Ie: like paint thinner, a little goes a long way. In the
other direction, if you want to thicken an oil, you have to add so
much thick stuff that it becomes the overwhelming majority.
Therefore (if you believe you want the lowest viscosity recommended
for your ambient temperatures), you can actually use 50% or more of
a thicker better protecting oil, and 50% of the thin viscocity you want,
and the result will have half the protectant additives and be 90% or
more toward the viscosity you want. My tactic is to use a mix of
0-40 Mobil-1 and some of their Mobil-1 truck/SUV oil. Their motorcycle
oils are very good too, but for 4 times the money, they aren't worth
it to me....

 

Sorry to beat this one, but how can one make recommendations for oil? What criteria is being used? Lower consumption?

reputation?
what Porsche recommends?

I mean saying "the motor didn't blow up when I used Silkolene 5w40" isn't really a data point to make a decision.

Running Used Oil Analyses from one fill to the next, and getting an expert to tell you what is going on in the engine is the best you can get short of teardowns and inspections of the parts!

I go with what the mfg recommends if the car is under warranty.

I collect UOAs to see what the oil is doing AND to have evidence of the wear and maintennace of the motor.

Here is an excellent article on oil- beware, it is not lite reading but it is another way to look at oil:

http://www.ferrarichat.com/forum/faq...=haas_articles

A

PS Amsoil 5w30 and M1 4w30 are pretty close (10.5 cps and 11.3Cps at 100C respectively) I thought amsoil might be thicker even though they are both "5W30"... there really is a lot of variation between Mfgs on what they label the oil (ie "5W" vs "10W", etc)

 

Re: redline

I would NOT use any oil in a street car that is not certified and does not have adequate additive packages to maintain stability over the course of the intended change interval.

A

PS A perrenial favorite on EVERY board: arguing about oil!

 

I like that article, good reading.

 

Thank you!!! This will help!

 

One reason Redline street oils are not certified because the levels of additives are above the API limit.

 

Actually, the primary reason more oils are not approved by Porsche is because many refuse to provide Porsche with the financial incentive to get on the list. Like the tire companies, it takes a great deal of money to get a car manufacturer to mentioned your name, let alone actually use your product.

This is why you see approved products one year and then unapproved when the contract expires, even tho the product has not changed specs.

 

Yeah, but wait a minute. How can we trust a Ferarri guy who says:

"It is time to introduce the concept of lubrication. Most believe that pressure = lubrication. This is false. Flow = lubrication. If pressure was the thing that somehow lubricated your engine then we would all be using 90 weight oil. Lubrication is used to separate moving parts, to keep them from touching. There is a one to one relationship between flow and separation. If you double the flow you will double the separation pressure in a bearing. The pressure at the bearing entrance is irrelevant.

In fact the relationship between pressure and flow is in opposition. If you change your oil to a thicker formula the pressure will go up. It goes up because the resistance to flow is greater and in fact the flow must go down in order for the pressure to go up. They are inversely related. Conversely if you choose a thinner oil then the pressure will go down. This can only occur if the flow has increased.

It seems then that we should all be using the thinnest oil money can buy. This is partly true. Let me use my 575 Ferrari Maranello as an example. I drive this car around town. The manual of this car states the target pressure is 75 PSI at 6,000 RPM. The gold standard is that all engines should have a pressure of 10 PSI for every 1,000 RPM of operation, not more, not less. After all, you do need some pressure to move that oil along, but only enough pressure, not more. More pressure is not better, it can only result from the impedance of oil flow. Remember that oil flow is the only thing that does the lubricating."

 

Great article...good debate...I'm sick of hearing how all of Porsche's decision are simply financial (Mr. 1999) and not for the good of the car/performance. Prove it or go stop please.

ps. My mechanic said not to use Redline as it does not contain detergents...and I am not tearing my motor apart every other week (like race teams do). If you use it, he suggests, at least every other fill use an oil with a detergent in it. I've got a good mechanic BTW.

 

I remember some time last year I had a heated discussion with 1999porsche911 regarding oils etc.

Now, what us Euro guys have is a dedicated oilman (which I also mentioned before) who recommends oils to us Porsche/Ferrari/TVR drivers (to be honest most high powered vehicles) he is an independent and will recommend individual oils such as Silkolene, Fuchs, Motul, Mobil, Castrol, Amsoil to name a few. He can be found on most Euro forums and is pretty much highly respected.

I sent him the link regarding the test and his reply was exactly the following

Steven,

Give me a couple of days and I will get back to you.

This is an American test and the test method is very amateur if I recall and does not tell the whole story or even a small part of it.

I am consulting with the Technical Gurus at Fuchs/Silkolene regarding this test as I have forgotten the problem with it in detail and want to give a detailed reply to you.

Give me some time to revert. Although the winner is not in doubt, our tests of this product do not prove it to be superior in any way to many European oils when chemically tested.

Regards
Simon
Opie Oils


I run on Motul 300v for my Turbo and find that the outcome of the Motul product very hard to believe (like Vicious mentioned) We ran their oils in Pro Motocross bikes reving out at 10/11k+ (and single cylinder I must add) plus most other teams used Motul and if it was this poor we would know about it! I'm taking this test with a pinch of salt until I hear back from my oil guy to say otherwise!