I know the manual says Mobil 1, 0 - 40.

1. Why? Why only Mobil 1?
2. Why 20K miles between service (no need to get into a discussion on "I changed mine at 3K" ... I'm talking about what Porsche recommends.

Anybody?

Is Mobil 1 truly synthetic or not anymore?

Debated awhile ago. Utlimately Porsche has to choose which engine oil works best for them and they consider a number of issues including warranty, their own internal tests, engine life, the Porsche engines complicated engine oil structure as well as supplier relationships ($?). Mobile 1 is a true synthetic. This is the other tread:
Redline Oil

Hopefully, this will answer some of your questions:

1. Porsche has an exclusive deal w/ Mobil 1. I don't know the exact details, but I'm pretty sure it involves promoting only Mobil 1 in exchange for deep discounts.

2. This is under "ideal" conditions -- highway driving at reasonable speeds, using high-quality gas, no dusty roads or conditions, etc. Part of it is the large volume of oil in the engine (nearly twice what a small-block Chevy would take), and part of it is just how much better and more durable the synthetic is vs ordinary dino-juice.

3. As far as I know, Mobil 1 is still fully synthetic.

From personal experience, I can tell you that Mobil 1 is good stuff. Several years ago, I pulled the engine from my old Typhoon at 46K miles to upgrade it. When I removed the heads, I was amazed to see how good the cylinder bores looked -- they looked almost brand new, with virtually all the factory cross-hatching still visible.

However, from what I've read, and from talking with very knowledgeable folks, Red Line and Amsoil synthetic oils are just as good as, if not better than, Mobil 1. I've used Red Line tranny and gear fluids (which are great), but haven't bothered to try their, or Amsoil's, motor oils only because Mobil 1 is much easier to get around here.

Chows - Not only is Mobil 1 good stuff and a real synthetic, you should only use the recommended weight of 0-40w. While not a true dry-sump oil system which uses a separate tank, the oil system on the Cayman does have many of the direct oil-delivery features of a dry sump system. One of those that is critical is the lifters, which actually "inflate" with oil from the system. The holes that allow oil into the lifters are quite small, and the 0-40w allows the maximum amount of oil to be pumped into the lifters, even when the oil is cold and thick.

The 20K between service is something PAG engineers have come up with as probably the best compromise between keeping the car in good shape and not whacking the owner's wallets too hard in the process. To be fair, the service intervals on Porsches have lengthened over the years. One of the things on the old motors that needed servicing more often than present day was the mechanical lifters needed adjusting at least once a year or 10k miles or so. Not true with the lifter system now in use.

brad

The only reason Porsche singles out Mobil 1 to rec by name is money. Mobil pays for that marketing advantage. There are other "Porsche approved" oils listed periodically in Porsche's bulletins. AFAIK, the most recent listing for late model Porsche's is:

Castrol Syntec 5-50
Mobil1 0-40
Mobil1 5-40
Havoline F3 Synthetic 5-40
Valvoline Syn Power 0-40
Valvoline Syn Power 5-40

I use M1, but would not be afraid to use any of the others.

As said above, there are several excellent quality non-approved oils distributed by smaller companies.

BTW, Porsche hasn't used mechanical lifters for more than 10 years (964).

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Dan

I know Mobil 1 is an excellent synthetic and assume Porsche recommends it because of quality and some contractual relationship. I assume Castrol, BMW (I have no idea who makes it for them) or any other quality synthetic would work just as well.

Metallurgy and production methods have improved quite a bit since the 1960s when we used to change oil every 3,000 miles. Once again I assume Porsche knows what it is doing and doesn't want its engines self-destructing at 75,000miles. I feel pretty comfortable with the longer service intervals of modern engines and generally follow the manufacturer's recommendations. I haven't had an engine problem yet in any of my cars.

Alan

Just visit the oil forum at http://www.bobistheoilguy.com/. Spend some time there and I am sure you will be believer in Mobil 1. Every car I had gets only Mobil 1 or Royal Purple synth. A lot of performance vehicle have M1 oil prescribed to them by factory.

Also, I may be wrong on this, but the last time I read, Mobil 1 and Royal Purple are the only two true synthetic oils sold in US. Castrol and others take dino oil, modify it, and than call it synthetic. Again, don't have a link to that, but I believe Mobil complained to FTC and caused a lawsuit for other manufacturers (like Castrol) that merely modified dino, instead of doing full synth.

Again, spend some time at the site I linked. I have been sent there every time I had oil questions in other forums.
They also have very good oil filter review.

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'07 Porsche Cayman S: de-snorked... more mods to come. '05 Dodge Magnum RT: catback, high-flow cats, custom intake, projector headlights, SC FlashPaq... and on and on.
Blog: leanstartups.com

Santa Fe, that thread does not answer my two questions

Thank you all for answers

I CAN believe Porsche cut a deal

As to 20K miles ... that about the most extreme I've seen. like many, no way is it going 20K.

As to synthetic ... I asked because there are some reports that Mobil 1 is no longer truly synthetics. In fact, if you go to their website and read whats in different versions, some do use dino oil (not the extended life version). Something about a lawsuit Mobil 1 lost against Amsoil?

I believe you are wrong on this.

Amsoil, Pennzoil, Castrol, and many other brands manufacture and sell true full synthetic oil and is labeled as such.

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I will track down the source.

Hey Chow not suggesting the other thread had the answers just thought the conversation would be interesting re other choices. Here is what Mobil say about the oil that Chow references "Is Mobil 1 with SuperSyn Technology a fully synthetic motor oil?
Yes, it is. To meet the demanding requirements of today's specifications (and our customers' expectations), Mobil 1 with SuperSyn uses high-performance fluids, including polyalphaolefins (PAOs), along with a proprietary system of additives. Each Mobil 1 with SuperSyn viscosity grade uses a unique combination of synthetic fluids and selected additives in order to tailor the viscosity grade to its specific application."

And their marketing "Mobil 1 with SuperSyn Technology exceeds the latest industry and OEM requirements. It is designed for vehicles under warranty and will provide protection for the maximum oil change interval recommended in your owner's manual or by your oil life sensor."

I do have some long related experience in this area. Mobil 1 is excellent. I hate to admit it since the company I spent so much time with didn't have quite the same results with its regular oil.