Seems to be a decent majority sticking with the 0w/40 Mobil. I'm not opposed to that at all as many of my previous cars also called for it.

 

In the LN engineering article on the IMS bearing issue they state that Castrol Syntec 5-40 is an "excellent choice" for the 997.1. I have always used Castrol for all DD's and sports cars, and I do on my 05 C2 as well. I was on the fence between M1 and Syntec but the LNE article swayed me.
I had 1400 miles and 9 months on the Syntec and I changed it 2 weeks ago. I sent a sample of the old oil to Blackstone for analysis. Came back with all parameters spot on and the additives at the original level (no change). They said I could easily run the engine longer on the oil before changing it, but I figured 9 months was long enough to have the same oil in the engine. They also said 'great engine' which was reassuring. Of course Mobil 1 must be a great lubricant or it wouldn't be recommended by Porsche.
One caveat on the Castrol however for older cars with flat tappet engines. They have reduced the amount of ZDDP (anti-wear additive). There are several oils that are made for these types of engines if you look on the internet. One dino oil I know of is Valvoline VR-1, it has a good amount of ZDDP in it. (I think 11 PPM).

 

I use the Castrol Syntec 5W40 in my Touareg, great product as well.

 

I ran Royal Purple exclusively in my previous turbo charged car (not a Porsche). Great oil, never had any issues. Not sure if they have the proper weight available for the 997 however. For those that do more spirited driving around town with occasional track use and live in a moderate climate, I recommend Mobil 1 5w-50 if you can find it.

http://www.mobiloil.com/USA-English/...ilability.aspx

 

Castrol Syn 5W-40 here.

Although M1 0w-40 is Porsche approved and used by dealers it is by far not the best oil for our engines. The addatives and characteristics of M1 0w-40 are available for public viewing on their website and sometimes on the back of the bottle. You can refer to LNE for a run down of what the different numbers mean.

In a nutshell, M1 0w-40 is not the greatest when compared to other Porsche approved oils. It has reputation as a "thinner" oil. M1 15w-50 is great but not Porsche approved, although many on this forum run it.

Castrol Syn 5W-40 is probably the best Porsche approved oil you can buy without going to the more expensive Motul oils.

I also recommend not using the 15K Porsche recommended change interval and instead sticking to 5K change intervals or after every track day.

Jason

 

My dealer uses Mobil 1 5W40.

 

Which one specifically? The only 5w40 M1 I know of is Turbo Diesel Truck, which a lot of people including myself run- it's got 100 ppm more ZDDP than 5w50- 1200 PPM vs 1100 PPM for 0w40 and 5w50.

1200ppm isn't enough to harm cats IMO- keep in mind I have a 996, so these cars were built before there were such stringent limits on the ZDDP package by the EPA.

Plus- I'd rather replace my cats than my motor- then I have reason to buy a Europipe! The Turbo Diesel Mobil 1 is approved for gasoline motors by the way.

 

I suspect it's that one, as I do not think Mobil 1 produces any other 5W40.

 

I've used Castrol Syn 5w/40 in the past with success as well and probably prefer it to M1.

As an added bonus, Advance Auto Parts has the Castrol on sale for $4.99 instead of $7.99. Hard to beat 9 quarts for $45!

 

Klotz 0w40

 

I Like the Motul but I plan to try the Syntec next. Bought it on sale at Advance too. Hard to beat.