YIKES! If those are his words, don't let him ever make an oil choice for you.
0W will help with cold start flow, as it has a lower viscosity/pour point vs 5W.
W30 is a lower viscosity then W40 and offers less hot viscosity/protection/film strength vs a W40.
Run a 0w40 or 5w40 year round.

 

+1, this is the main cause.

 

I'm a life-long Castrol guy, will continue as long as the specs stay good
5w50 Castrol Edge in my GT2 (+the other Mezger 911's) for 3-season use.

 

thicker!= more protection

 

Rob, I didnt understand your point on "40" and "30".
The 40 in a 5w-40 simply means that the oil must fall within certain viscosity limits at 100°C. This is a fixed limit and all oils that end in 40 must achieve these limits. Once again the lower the number, the thinner the oil: a 30 oil is thinner than a 40 oil at 100°C etc. This is just for hot temps

 

Nice data Rob, thanks for sharing. Although I don't regularly use Castrol (I buy everything through worldpac for convenience as I run my shop stuff through there), I highly recommend it, for whatever that's worth...

I use Motul for most WC Porsche stuff now, it is recommended by Porsche and LN Engineering. (But this is only because somebody got paid somewhere along the line.)

 

Yes but thinner = faster! Just don't go too thin... lol

 

This is a very good point to make. most shops arent pushing a certain brand because its the "best". Some money was exchanged at some point

Even the porsche approval list is subject to procedural and monetary bs. Its not like Porsche is actually testing all these oils

 

Exactly.

 

That's exactly my point. No idea why the mechanic would be recommending a W30...I can understand the push for a 0W for winter use, but not lowering the hot weight/viscosity...

 

So for winter specs, what would be the best choice?

 

He didnt push the "30 or 40", he just said 0w-30, and I agree why not 40?

However the point was, as it is not very hot in the summer, the "30" would be ok....

But again, we are talking for winter drive

 

Thanks!
I can't beat the performance/value that Castrol offers.
Like Motul products but the can be expensive(I lean towards frequent intervals vs 'boutique' fluids).
In the case of Porsche recommending Motul, I wonder if its less about marketing this time around, and more as fight against/C.Y.A. for the various engine wear issues they've been having...Motul is good oil...

 

W30 is in general too thin...alternatively you could argue 5w50 is too thick(actual cold viscosity) for cold weather use, although the added residual film strength might provide initial start-up protection...
All watercooled 911's use a oil to water heat exchanger, our oil temps are very consistent for street use regardless of outside temps/climate.

 

I would lean to a 0w40 or 5w40 (I like mobil 0w40 more than its 5w40)....however if you want to run a quality 0w30...German Castrol 0w30 probably the only one I would entertain for this application. Its very near the 40 weight range when up to temp and has very good low flow properties. The oil has a cult following for a reason.

CT sells it in 1 liter containers only. Says "made in germany" on the back.


Not my endorsement to use it, that is ultimately up to you. Do i think you will hurt your engine running it? absolutely not.