My local tuner shop also told me not to use 15-50 oil on my 997.1.
Does anybody sell 5w-50 mobil 1 on internet?

 

I found 5w-40 Motul 8100 X-cess on the internet. It is a Porsche approved Oil and allot of the AudiVW Turbo tuners seem to use it.

The only change I have noticed is the engine seems quieter and I think my oil consumption is less, but I haven't documented that yet.

 

Something to understand is that at normal operating temps the 50 weight oil is the same weather it is 5w-50 or 15w-50. The 5 and 15 refer to the cold start viscosity level or how cold the oil is rated for and the W means its been tested and received an appropriate SAE viscosity rating. The difference between the 5 and 15 is a matter of temperature at the cold start. Here in Southern California I will never see a cold enough start to warrant anything lower than 15W. But again, once the engine is at operating temps the 50 oil will be equal. The cold start viscosity rating is achieved through the addition of additives.

This is a pretty general explanation but is how I understand oil grades.

Again this is a touchy subject so I realize there are a lot of opinions and counter points. I have just not had great experiences with 0W-40 and wanted to switch to a readily available 50 weight oil for that reason and the other reasons listed above.

Jason

 

Not sure what do you mean by 'not great experiences' with 0w-40, 997 engine is designed to run on it. Did you have an engine failure? 0w provides proper lubrication during startup, as 0w oil is simply more 'liquid' than 15w at same given operating temperature. My concern is exactly opposite, that 15w oil will be too thick during startup.

More interesting concept is to 'mix' 15w-50 with 0w-40 in some proportions, but, again, it is quite a shady area for me.

 

I am not sure why to use 5w-40, point of going with other oil than 0w-40 is to go higher than 40 to improve lubrication when engine is extremely hot, like during tracking or auto-x when you redline it constantly.

 

My reasoning 0W is just too low for where I live. Wanted to try something different that was on the approved list.

Speaking of the approved list. On my copy 2/06 there are know approved 15W oils and only one 5w-50.

I like the Motul brake fluid and had heard good things about their oil. So far so good. I also think I read somewhere the 5w-40W users were experiencing less oil consumption, but not sure on that count yet.

 

What approved list are you talking about? Only approved oil for 997 car is 0w-40 Mobil 1 from what I know. Is there anything else? Where?

I understand entire oil system in 997 is optimized for density of an 0w oil, is it not?

 

The approved list is a list of those companies who paid to get Porsche's approval. Yes, that is a fact. You must spend alot of money to get on the list. It does NOT MEAN that the list contains the best oil for your car but only that alot of money has been spent by those companies on the list.

 

IE 8 is not letting me add an attachment so send me a PM with your e-mail and I will send you the Porsche Aprroved list.

 

It does not mean that 997 engine internals were built in anticipation to pump, like, 15w-30 regular thick natural oil, one can get for buck per gallon right?
so right question is perhaps - what can 997 engine really benefit from, considering 0w-40 is a default oil it needs and also considering set of existing manufacturer recommendations?

we can discuss endlessly what gets into that list and how but still that list will be used against you if you put something non-recommended into engine on warranty and your engine dies due to the lack of lubrication as internal oil channels got clogged.

 

...at least that is what is in my manual.

I think DFI spec cars Owner's Manuals must be different :

 

If 5W50 oil works fne in your engine, 15W50 and 20W50 will work just fine and 15W50 is a better oil. Flow at cold startup of 15W50 is fine, even below 0F. 0W40 is not the default oil, nor is it specifically recommended over any other oil on Porsche's approved list. It just is the factory fill, which is the result of considerable discounting by Exxon/Mobil.

 

I have no idea where do you get your assumptions from. I am looking into approved oil list right now and from all different brands only combinations are 0w-40 or 5w-40. Single one 50 oil is mobil 1 5w-50.

There is not a single one 15w50 or 20w50 so I presume you use those 'better' oils on your engine at your own risk.

 

Did I say anything different? My point is, if a 50 weight oil is ok for your engine, it does not matter wther you use a 0W50 or a 15/50 or 20/50, depending on the ambient temperature the car is stored in.

 

No doubt a touchy subject , but your explanation is correct. In the South, I could probably get away with 15-50 as well...based solely on that general knowledge of the oil.

more detail: http://www.aa1car.com/library/oil_viscosity.htm

My take away from that article is there is probably more to it though - like the break down in wider cold/hot range viscosity oils - which may or may not apply to Mobil1 specifically. Or how different engine builds work better with higher or lower viscosity oils. Is my engine a racing engine or a "latest trend" racing engine or neither? What to to, what to do?

It does make me wonder sometimes though why we'd even buy a car from a company who does not know and properly document what oil should go into their engines or who would recommend something less than ideal.