1999Porsche911

Now for a few facts:

Porsche does not recommend 0W40 for your engine

Porsche recommends using one of their approved oils

Using the approved 5W50 oil will reduce both leaks and oil burning for those who have those problems.

Using the approved 5W50 oil will provide you with better shear protection and better oil pressure over the Mobil Water.

5W50 provides you with equal protection as 0W40 down to -25C. Porsche makes no statement on which oil is better at higher temperatures and load, but the oil manufactures, approved by Porsche, do. 5W50 wins that category.

Therefore, from Porsche's own documentation, for those who drive in temps above -25C, 5W50 is as safe and as preferred as 0W40. It is also a fact that 5W50 provides better protection than does 0W40 at higher temperatures and loads.

So, what basis do you use now to argue that 5W50 should not be used and that 0W40 is the best?

bgiere

ah.hhh..the Master has spoken! amazing.

Benjamin Choi

I think Porsche listed 0-40 amongst others on their recommended list, but wasn't specific/detailed as to what's better than the other maybe save for outside operating temp?

But where I think 1999Porsche guy is flying pig in the sky is how he's stating reasons why 5-50 is better than 0-40 for our P-cars.

Has anyone met 1999 in person? Is he real?

I just run Mobil1 0-40 btw.

1999Porsche911

Excellent technical reponse! I didn't expect any of you "Porsche knows best" people to have an answer.

Typical avoidance of the subject rather than acknowledging the facts.

1999Porsche911

How about some specifics why it is not better?


Is it true or not that the 5W50 provides better shear protection at higher loads and oil temperture? If you agree with that statement which is factual as reported by the oil manufacturers who are approved by Porsche, then, why is better shear protection NOT better for you P-car?

If you do not agree that 5W50 offers better shear protection, then you are ignoring facts and simply not interested in any answer but your own.

BruceP

Sigh. When will you learn that it's not our obligation to prove you wrong? It's YOUR obligation to prove PORSCHE wrong? You're the one challenging the 'official' version, so the onus of proof is on you.

It's just such a weak defense, last practiced with any effectiveness in Salem, I believe.

DreamCarrera

I don’t recall anyone saying that Porsche recommends 0w-40 and only 0w-40. I think most people are aware that Porsche has a long list of “approved” oil choices.

However, I take the fact that all new 911s come filled from the factory with Mobil 1 0w-40 as a recommendation by Porsche. After all, given the wide variety of Mobil 1 viscosities, why would Porsche not choose the one best suited for the engine?

MrBonus

What basis do you use now to argue 0W40 should not be used and that 5W50 is best?

See? I can do it too!

1999Porsche911

Porsche states that they are equal down to -25C. The approved oil companies state that the 5W50 is better at higher temps and loads. You only need to look at the specs of each for your proof. No magic here. No opinions, just facts for those who care to look.


IF 0W40 was the best oil for your Porsche in all conditions (as many claim over and over again on this forum), why on earth would Porsche recommend other viscocities, including 5W40 and 5W50? Could it be that there are conditions that might warrant a higher viscosity oil?

Tippy

What I still dont understand about German cars is why they use 40-60 weight oil in the first place? Most American cars and trucks use 20-30 weight.

Blackness

I'm a real dumbass so you need to lead me to the trough. Can you provide a link or quote from a document from one of the approved oil companies that states this in plain english?

dresler

A quiz...

1) At warmed-up operating temperature, what is the viscosity of 5W-40 Oil?
2) At warmed-up operating temperature, what is the viscosity of 0W-40 Oil?

1999Porsche911

Depends what brand oil. Some 0W40 oil has a lower warm cst than 5W40 and some have a higher. Rules allow for a 40-weight oil to have a minimum viscosity of 12.5 cSt at 100°C (212°F) and must be less than 16.3 cSt.

dresler

holy crap that is a 20% variation.

If 0W40 has 12.4 centistokes and 5W40 has 16.3, there may be a basis for some of the arguments on this thread.

But in a "perfect" world, they are the same. Read the MD's oil stuff, looks right to me. but, as all physics majors and engineers know, MD's aren't real scientists. j/k.

1999Porsche911

You, it is a big range. There is more to oil than you can learned on the internet, which some people here refuse to accept.