Porsche Enthusiasts Club Forum

Can you post some links to the datasheets you have seen with this Wes?

One thing to bear in mind is that there are several Mobil oils, in particular there are about 3 types for each grade.

"Mobil-1" is one type, it is a fully synthetic oil made from pure basestocks.

Then you have "Mobil" fully synthetics, which are a budget oil, still 100% synthetic, but not the virgin basestocks.

And last of all you have the "Mobil semi synthetics" which are made (From memory) with 30% synthetic content and 70% fossil oils.

Not sure which oil he was refering to when he said "As opposed to say a standard 10w40 which is only (typical) 850 parts per million" as I think he might have been reffering to another brands 10w40 which he might have thought I was comparing too.

It is also essential to make sure you read the european datasheets, as they have told me in the past that in the USA their oils are of a completely different specification.

I will ask him for clarification.

This is the current UK data sheet for Mobil 1 Extended Life 10w-60:-

http://www.mobil.com/UK-English/Lubes/PDS/GLXXENPVLMOMobil_1_Extended_Life_10W-60.aspx

On the face of it, it seems fine but I wish they'd be more transparent about simple oil specs - other large companies make their specs readily available. I think it will put a lot of people off in the end.

I'm no expert on all the various API spec requirements but it looks to meet or exceed all the latest specs which may not be a good thing with regards to older manufacture engines.

I've spent too much money on my latest engine build and there are also more and more parts becoming no longer available from Porsche for the 924 2.0L engine (con rod bolts, main bearings, valve springs). This means I will be using the best synthetic oil I can find when it's all up and running, probably a triple ester.

In contrast to Exxonmobil/Mobil 1, I got an email response from Millers Oils in ~3 minutes.

Their CFS 5w-40, 10w-50, and 10w-60 have 1400ppm ZDDP.

CFS 10w-50 is what I use.

Seems pretty good!

Regarding the Mobil 1 Extended Life 10w-60 oil and the data sheet mentioning it meets or exceeds API SM spec.
The actual grade of 10w-60 means that the oil is exempt from lowering ZDDP content.

Any oil marked API SM/SN, ILSAC GF-4/5 or ILSAC CJ-5 in grades SAE 0W-20, SAE 5W-20, SAE 0W-30, SAE 5W-30 and SAE 10W-30 cannot have sufficient ZDDP because the grades ARE NOT exempt.
I doubt anyone would consider using these grades in our engines anyway.
API SM spec oils in the above thin viscosities will contain between 600 and 800ppm ZDDP.

Consider 1000ppm ZDDP as an absolute minimum for decent anti-wear protection in older design engines - in particular so-called 'flat-tappet' designs.

Interestingly Mobil 1 15w-50 has been relaunched in the USA due to demand but the spec has changed and Exxonmobil will not elaborate on all the changes.

Doing any kind of research on oils makes you lose the will to live!

I hope they re-release it here and are a bit more open regarding the specification!

Not sure of the ppm in this but the product material data sheet for Petronas Syntium 1000 shows Zinc Alkyl Dithiophosphates (ZDDP) as between 1-2.2% so in 4 litres between 40 and 88 ml per container and currently on offer at Eurocar parts for £12.99 plus 25% discount so even cheaper.

That is a seriously massive amount of ZDDP!

1400 ppm in a 5L can of mobil one motorsport is about 7ml by my calculations, so 40 to 88ml of ZDDP is seriously loads. Not sure if it is possible to overdose an engine on ZDDP?

It did seem high when I saw it I thought this can't be right but only going of the Petronas material data sheet which states 1-2.2%, I suppose at least it has some in and after getting 8 litres for £18.88 of the 10W40 it seems to have stopped my S2 smoking after engine braking, also the oil pressure is more stable at temperature. Replaced 5W40 fully synth that was used for the service only 1000 miles ago (in March) so to date well chuffed.

Which fully synth 5w40 caused the smoking and unstable oil pressure?

can you not get zddp as an additive?

Would remove any doubt.

I did look into this, and even a chemical company which supplies chemical compounds by the drum to industry could not find a bulk supplier or even a proper scientific documented method to produce it from basic compounds. They commented it seemed to be an oil industry secret....


.... Or maybe it was too much effort for them to look into properly!

It's possible - even likely - that it's actually a by-product that forms in the oil as it's brewed that just happens to be useful.

The petro-chemical industry is something of an enigma!

Which fully synth 5w40 caused the smoking and unstable oil pressure?[/quote]

Not sure which oil caused the smoking or if that was the real cause but it was probably Mobil 1 or Silkolene both of which I have used before with no issue.

A couple of things I also found and fixed at the same time was a loose balance shaft belt and cam belt that was catching on the casing and both needed adjustment and also cleaned the distributor and rotor arm contacts, don't think this would have caused the smoking probably more down to the viscosity.