911dev

I'm looking for opinions/guidance on oil viscosity. I have a .2 GT3. The manual indicates that I may use the factory filled 0w-40 or 5w-40 or 50. Apparently, 0w is used for all temps and 5w is not recommended unless the temps are greater than -25C. I don't know of any of us driving these cars when it's that cold. So, my question is why even bother with 0w? It seems that it is recommended for the convertors and better fuel mileage rather than protection.

I'd like to go with 5w 40 or 50 but wanted opinions first. Mine is a street driven GT3 but it is not babied in any sense of the word. Would anyone recommend a type other than Mobil One? Castrol Syntec for instance? The temps I drive in range from 35 F (maybe 30 occasionally) to 95 F. I don't drive hard when it's 85 F and up and don't drive much at all if it's above 90 F.

beentherebaby

If the manual states that you can use 0W-40 and 5W-40 viscosities, I don't see the issue.

The 0W flows a little better cold. If your engine never sees temps below zero F it's a moot point.

The brand is of less importance than the oil spec. If you are using a Porsche approved oil of the correct viscosity for the application, then you're fine. That's why Porsche and all major car makers actually test and approve appropriate oils for a given application. Any of these approved oils should serve your engine well.

axhoaxho

I am in California, last time I had an oil change at my dealer, they said now they use Mobil 1 Formula M 5W-40 exclusively.

Regards,

911dev

It's not a matter of if I'm okay using what Porsche recommends.

911dev

Good to know. I am trying to find out if the 5w spec is a Euro blend; I don't believe it is.

ADias

Which dealer? We have to check the oil properties. The good thing about the Mobil 1 0W40 is that it has a higher phosphorous content than the other oils in the series.

911SLOW

Porsche current Mobil approved oils are valid for WW and for all Porsche production vehicles with the exception of the Cayenne V6 from 1984 and on.

Mobil 1 SAE 0W-40 0W-40
Mobil 1 SAE 5W-40 5W-40
Mobil 1 SAE 5W-50 5W-50
Mobil Synt S 5W-40
Mobil Syst S 5W-40
Mobil 1 FF 100 0W-40
Mobil 1 Arctic 0W-40
Mobil 1 Formula C
Mobil 1 ESP 0W-40
Mobil 1 New Life 0W-40
Mobil 1 Peak Life 5W-40
Mobil Super 3000 X1 5W-40
Mobil Super 3000 X2 5W-40
Mobil Formula X2 5W-40

John

deutschmick

Thanks for the list.

Beautiful Dobie also!

911dev

That's what I asking about; stuff like this. Dumb question, but what does a higher sulfer content have to do with a good oil?

I know that Euro spec is a step above in the synthetic rating. 0w is 5w is not, why?

beentherebaby

Is this a trick question or a popularity contest?

If it's a popularity contest, who gets the deciding vote?

911dev

Sorry if I am unable to convey what info I am in search of. If it'll make you feel better, I'll vote for you.

Macster

Higher sulphur content bad. Combines with water to make acid. Also, as engine consumes oil the sulphur can work to help shorten the life of the sensors and converters.

Back in 2002 when I was looking into diesel powered vehicles there was some mistaken belief that sulphur in diesel fuel was good cause there was some problems with diesel fuel pumps when using low sulphur diesel fuel. (These pumps are extremely sophisticated and expensive cause they must generate very high pressures (>15000psi and more) and help deliver very precise shots of fuel every power stroke of the engine's cylinders.)

People blamed the absence of sulfphur when the real problem was the process by which the sulphur was removed at the refinery. It had a side effect of affecting the lubricity of the diesel fuel. A change in this process restored the lubricity of the fuel.

Sulphur in fuel or oil is not a desirable element.

Sincerely,

Macster.

Macster

0w-40 is really geared to lowering hydraulic friction upon engine start. A cold engine is a really dirty engine. Anything a manufacturer can do to clean up a cold engine it will strive to do. Total engine emissions are measured/considered -- in Europe/UK not only fuel mileage but CO2 emissions play a big role in a car's cost to register -- and all automakers seek to reduce these numbers by any reasonable (and possibly unreasonable) methods they can.

There is not much an engine designer can do to clean up a cold engine's emissions. The sensors/converters are too cold to work so the engine controller is running open loop and the engine is being fed a rich mixture.

If you live in area where the temperatures require a 0w-40 oil use it. If not then a 5w-40 or 5w-50 oil is ok and maybe better as long as the oil meets the requirements Porsche sets forth for oils suitable for use in your car's engine.

Sincerely,

Macster.

beentherebaby

I wanted the last vote...

In your original post above you theorized that 0W-40 was for "convertors and better mpg". The 0W oil viscosity rating has nothing to do with "convertors and mpg". 0W means the oil flows easier at cold temps - which is good as the oil gets to the extremities of the engine sooner than with a thicker oil to reduce cold start-up engine wear. See the viscosity info. at the link below.

As the viscosity info. explains a 0W-40 weight oil has the SAME hot viscosity at 212 F as a 5W-40 oil or any other "40" weight oil. The cold viscosity is the difference in the oils not the hot viscosity. All modern oils must hold viscosity during the prescribed OCI so it does not matter if you use a 0W-40 or 5W-40 Porsche approved oil for the temp range you operate your engine in.

http://www.ideas4ag-ed.com/uploads/3..._viscosity.pdf

As far as which oil is "the best" or "better" it's virtually impossible to determine without actual objective oil sequence testing of the specific engine and oils in question. That's what Porsche and other car makers do before approving an oil for use. That is why I stated that any of the approved Porsche oils of the correct viscosity for the application will work just fine. No one could possibly determine if one oil is "better" than another for the application without the extensive oil test sequence that the car makers use. It would be pure speculation to claim the performance of one oil is better than another without actual objective oil sequence testing. See the ACEA A3/B4 oil test sequence as an example. The A3/B4 sequence is the basis that most Euro car makers use to develop their engine family specific oil spec requirements.

http://www.acea.be/images/uploads/pu..._LD_and_HD.pdf

In addition you'd also need to quantify "best" to even compare oil performance data if you had it. Unfortunately this info. just is not available to the public.

BTW, your Porsche was meant to be driven, so enjoy it.

axhoaxho

Porsche of Fremont.