Porsche Enthusiasts Club Forum

Lots of people have recently been asking me about ZDDP and engine oils.

As a lot of people will know, ZDDP is Zinc Dialkyl Dithio Phosphate, and most importantly it provides excellent anti wear protection, especially in 944, 928 and 924 engines.

ZDDP used to be in lots of quality engine oils, when it violently increases in temperature it fragments and coats the metal surfaces with Zinc, particularly useful on gears, camshafts, flat top cam followers etc.

The Phosphate part then acts as a dispersant, i.e. makes any carbon produced, dissolve in the oil and not bung up the engine.

However, it was found that it caused problems with Diesel Particulate filters, so it has been dropped from a number of oils, it is also said to be less than friendly to catalytic converters, but it seems this is the new generation of cats, not the type used in the 1990's such as on our Porsche cars from the 80's and 90's.

Lots of you already know this.

Mobil 1 Motorsport used to be a desired oil, as it was an excellent product, but also had high levels of ZDDP (ranging from 1400 to 1200 ppm over the years) But Mobil 1 Motorsport was discontinued finally earlier this year.

It has taken some effort and harrassing of Mobil, but I now have the definitive answer that a lot of people have been asking me, and asking in the forums.

Mobil-1 Extended Life 10w60 does indeed include ZDDP, not only this, but it has 1300 Parts Per Million (PPM) which is comparable to Mobil 1 Motorsport 15w50.

I have also been informed by Mobil that their "10w40 semi synthetic Super 2000 X1" has 850 parts per million of ZDDP, which means this could be a useful alternative if you are on a budget and the 10w60 fully synthetic is a little too expensive for you.

The "10w60 extended life mobil-1" product is a fully synthetic, made from virgin base products.

The 10w40 Super2000X1 has a minimum content of 30% synthetic base products, where as some semi synthetic oils out there have as little as 1 or 2% to get away with calling it a semisynthetic.

I can now endorse both "Mobil-1 Extended Life 10w60" fully synthetic and "Mobil Super2000X1 10w40" semi synthetic as being perfect for our older Porsche models.

I hope this helps.

Worth knowing though it seems fully synthetic is a marketing term for some companies, keeps 99% of punters happy I suppose but I look for the triple ester PAO formulation, there does come a cost level though where just changing it more often comes into the reckoning.

That's good to know Jon, thanks for the info.

Thanks That's good as this is what Im running.

I had read the earlier thread on ZDDP with interest. What are your thoughts on Chevron fully synthetic https://cglapps.chevron.com/msdspds/PDS ... Format=PDF

The spec sheet lists zinc but I couldn't see ZDDP mentioned.

Reason I ask is Costco has 20 litre tubs of this stuff at much reduced cost than mobile1 IIRC 20 l is 40 quid.

That is a seriously cheap oil at that price!

I am a Mobil service centre, and it took me the last 6 months to get the definitive answer from Mobil as to the ZDDP content of their oil, not sure how long it would take to get it from Chevron!!

The thing is it would seem that Zinc and Phosphorous do not make ZDDP, but rather it is a compound in itself, which releases zinc and phosphorous.

Although I could be wrong.. A chemist I am not

Plenty of oils around that are SJ/SL rated which are higher in ZDDP than the current oils. Mine is running Total Quartz 7000 oil from Carrefour at £20 for 5L.
Always ran Valvoline VR1 Turbo in the 944 which is 15W/50, this is a mineral which I bought in bulk. The Boxster will be running 10W/40 which the Quartz is.
I've never been a particular fan of Mobil 1, once you get away from the marketing it is an OK oil sold at top price. But TBH make is irrelevant the issue is getting the correct spec with enough ZDDP. Note that the oil should either be on the approved list OR "0w40, 5w40, 10w40 and higher if they comply with ACEA A3 specification. The Quartz is within that.

Some good info here http://www.lnengineering.com/ims.html & here http://www.lnengineering.com/oiltest.pdf
Especially note the comment that a thicker oil could reduce the IMS failure issues!

What are your opinions on oil change interval Jim?

LNEngineering believe that IMS failures on Boxster, Cayman, 996 and 997 engines are down to the following causes.

Poor bearing design. Which includes material type, sealing and overall design shortcomings.
Forever longer oil drain intervals encouraged by the manufacturers.
Engines being driven too sedately
Too thin an oil being used in many cases

I would tend to agree with all of this for the flat 6 watercooled engines.

However I would also say there is a problem related to this that effects the 4 and 8 cylinder watercooled engines, as well as the flat 6 air cooled engines. Which is there is a large contingent of people championing long drain intervals, thin oils and the myth that sedate driving is good for an engine,

A few years ago, Porsche retrospectively re-specified their recommended oil for all Porsche models, even historically, which means that engines designed to run a 10w40, a 15w50 or even a 20w50 oil are recommended to be run on 5w40's as stocked by UK main dealers... As soon as they did this, we noticed a drastic increase in main dealer serviced cars coming to us with oil leaks and blue smoke issues, which in most cases was cured by switching the oil back to a 10w40 or 15w50 oil.

With the long drain intervals you have people like the author of a website calling itself an oil bible... It tries to say that engine oil could be kept in an engine for years without changing it, even if it was black as sack cloth, especially with modern oils it claims... It tries to also say the people, like myself, who recommend frequent oil changes are trying to cash in... Well I give up, in the meantime I will continue changing the oil in all my cars at least twice a year with the sound knowledge that a gram of contamination in your oil, is a gram of contamination in your oil, no matter how good the additive package is.

Why do I push mobil oil?

Well they spend a massive amount on advertising, this is true, they really do.. I would not be shocked to find out that 40% of what a can of mobil oil costs goes towards advertising. Which is not great.

The reason I am a fan of Mobil oil is the following key reasons.

1. They are consistent in quality over the years.
2. They perform well in a tangable way on the most punishing engines I work on
3. No one has a problem with Mobil.
4. They are the only oil producer who deal directly with me.

1. Consistency.
Over the years I have seen Mobil products (until the last year) stay the same pretty much for decades. Whereas I have seen Castrol, Shell and others bring in various oils, with new outragous claims (magnetic oil!!) only to be replaced by new oils with new names and buzz words.. Sometimes it is a bit like watching ladies product advertising, active lipozones, aqua, boswollocks... So I always knew where I stood with mobil, that is until they revamed the whole range late last year..

2. Good performance from my perspective.
Over the years I have worked on a lot of really oil punishing engines. 930 Turbo's, 964's, 993's, 944 Turbo's. Every other oil I have tried over the years (Shell, Elf etc) have displayed lower oil pressure when the engine is pushed hard for prelonged periods, this can be seen on the oil pressure gauges directly on the road but especially on the track

3. No one has a problem with Mobil.
I am in a position where some customers could not give a damn what I used, but some are really particular, and no one seems to have a hatred of mobil, other than the costs.. But almost everyone out there has an oil they hate.. I would alienate customers by using ELf, Castrol, Shell.. Someone somewhere would always be untrusting of one of those.. But with Mobil, no one has ever complained that we use it.
We have one customer who supplies his own Silkolene.. It is his choice and I have no problem with that, but everyone else that has been bothered to ask what we use, had nodded in a reasured way when they find out we use mobil oil.

4. They deal direct with me.
It took a while to get hold of the right person who knew what ZDDP was, to get to the bottom of what its content was in the new oil lineup.. But I was eventually able to get there.
Mobil deal with me direct, I buy from them, every 4 weeks they send out a chap to make sure I am happy with them, they do not even ask that I exclusively use their products. But most importantly, they deal with me direct.. Everyone else wants me to deal with a distributor who only knows the profit margin and little else.
Because I deal with mobil, I also have access to their labs.. Every Mobil service centre has access to have oil analysed by Mobil, which means that in the process of developing things, or diagnosing what happened to an engine, they are more than happy to run a full analysis on the engine oil, I like that.

To be totally honest, I would probably say you could use almost any oil in your engine, as long as it has the correct basis parameters and ingredients, such as ZDDP and being the correct viscosity.. most importantly, as long as the oil is changed on a regular basis, which isnt yearly, or even every 12,000 miles, but I would say every 6000 miles or 6 months, whatever comes first... Weather people follow my advice isnt my worry.. I follow it on my own vehicles and that is enough for me.

If Tesco's made oil, it conformed to the correct specifications, then that will probably do, synthetic, semi synthetic or mineral based.. as long as it was changed on a regular basis, it will probably be good enough.

I however use the oil I am most happy with, which happens to be mobil, for you it might be Comma, Fuchs, Total, Elf, Shell, Castrol or even A1 Motorstores own brand.. At the end of the day, when something in your engine goes pop, you need to know you did your best to avoid it, and to make choices which may avoid regrets later.

I was really pleased to find out the new mobil products I mentioned have sufficient ZDDP, I now know I have a few more years of warm fuzzy feelings that mobil oils in my cars are doing their jobs, and in customers cars they will be one thing keeping my customers engines working correctly and at least the oil I use will not be doubted.

Its all good

What are your opinions on oil change interval Jim?
Far too long. Most Synthetics are designed for long fill periods, 12,000-20,000 miles. Fine for the fleet buyers who want low down time & reduced service intervals. Also OK when the engine is new, once it has say 80K on the clock it may require a different oil grade. Also thin oils are purely for economy & passing the stupid EU tests, by giving quick warm up & less drag.
I understand very modern engines run tighter tolerances so don't need the 20/50s of old, but no one can convince me that oils that are 0W/x are for any other reason than very quick warm up & minimum drag from cold during emmisions testing.
For proof of this look at the servicing specification of cars that had long lives, lots of these went from 6K service intervals to 12K with no changes to the engine build.
I'll repeat the link http://www.lnengineering.com/oil.html as there is some fascinating stuff on there plus some links to a ton of other research.

I've always had the philosophy of reasonably frequent changes with an oil that meets MY requirements not the garages bulk tank!
Hence when the Boxster was serviced I provided my Oil in this case Total Quartz 7000 but would have used anything with a specification of ACEA 2007 A3/B4 API SL/CF, rather than the current SM etc.




LNEngineering believe that IMS failures on Boxster, Cayman, 996 and 997 engines are down to the following causes.

Poor bearing design. Which includes material type, sealing and overall design shortcomings.
Forever longer oil drain intervals encouraged by the manufacturers.
Engines being driven too sedately
Too thin an oil being used in many cases
I agree with all of this from the research that I've done. The overall design is very poor & I'm surprised didn't come to light during testing of the M96 engine. Interesting that the bearing the other end of the IMS shaft is an aluminium oil fed one that apparently dates back to a VW design of the 60's.

Yep, some VW engineer with a slide rule designed the bit that outlasts what the Porsche designer came up with by using the latest cad, simulation and modern scientific research into materials.

Call me a conspiracy theorist.. but..

Typically the IMS tends to last beyond the factory warranty period.
Porsche make many more cars than they did 20 years ago
Some people say that Porsche are flooding the market and diluting the exclusivity of the brand.

I think in 20 years, there will be as few 20 year old Porsche's on the road as there are 20 year old Porsche on the road today... I think it is reasonable to think that Porsche maybe knew what they were doing when they designed the IMS Bearing, the wishbones and the other Achilles heels which on the surface look like a mistake.

Hi,

actually all european data sheets for Mobil super 2000 x1 give a Phosphorous
content of 0.144 %.
And Mobil super 2000 formula P would be even at 0.18 %.

However, after writing to clarify this unusual phosphorous content, I am
unable to get any reply from Mobil UK or Mobil Europe. Also impossible
to reach their technical desk by phone.

I guess I have to give up

However in an old datasheet for Mobil Super S, Phosphorous was reported
at some 0.14 %.
And it seems that Super S was replaced by super 2000

Obviously Mobil do not care to clarify, let alone reply

But Mobil's attitude might perhaps even be interpreted as :
"We are Mobil corp. , why in the world could our data sheets be
incorrect... and how do you dare to even cast any doubts ?..."

So that P content may be correct in the end.

best to everybody

enri

I have had it confirmed in writing from Mobil regarding the ZDDP content in the Mobil Extended life 10w60 fully synthetic.

It did take a lot of work to get though.

I think the problem with getting this specific information out of Mobil, is most of their customer service people are only allowed to provide whatever information is on the publicly published mobil releases, such as datasheets.

Once someone asks for something else, there is always a chance that it is proprietory information, such as a component in their product which is an industry secret.. Yes ZDDP is not a secret, but someone in a call centre, or a customer care person who replies to emails, is not going to be an engineer, or even maybe interested in cars, and they do not have access or permission to release information to the public which is not already publicly released in documents.

I am really lucky to have access to some of their technical bods who are able to answer, but even they have to have permission before they answer a question not in the technical releases.

Unfortunately, Mobil stopped publishing the ZDDP content to their new range of oils, and substituted the phosphorous content in the same part of the datasheet, which then meant their new product line up no longer listed ZDDP and therefore without higher permission no one was allowed to comment on its content.

One of the problems of a big corporation.

I have just retrieved from my email the original communication from mobil on this subject and have copied and pasted it here.



Notice how the cocky bugger ends with "Ask me another"

I used to swear by Mobil 1 15w-50 motorsport and my father still uses it in his 3.2 Carrera.
However, I don't think I'll be using the new spec extended life 10w-60.

Their answer doesn't make sense to me. First of all the spec is supposed to meet API SM. I'm pretty sure that SM is supposed to reduce ZDDP to less than 600ppm?

Also your typical 10w-40 now has much less than the 850 ppm he suggests.

On top of all this, I've read that they now use lesser quality grade III base stocks.

Need to do more research but I don't trust oil companies at the best of times. Maybe independent oil analysis is the way forward but I'm leaning more towards the Miller synthetics now.