Oil for the 993 - decision made

[Guest]

I have finally decided on the best oil for my 993 at the next change. I have researched this matter for around six months. I have spent hours on various forums and have spoken to several people "in the know" who work in the industry. Here's an email which I received from a helpful engineer at Fuchs/Silkolene recently, on the subject of ester-based oils, which I keep being told far & wide are superior to type IV PAOs:

"Suggest our Pro S 10W-50 for your car. It's a full synthetic ester based material which has performed well in various high power engines for many years. Esters are not hygroscopic, they do have an affinity for metal surfaces so they tend to stay put after shut down giving good corrosion protection and they also help prevent the engine from running "dry" after cold start. For this reason are very well suited to engines which are used intermittently.

The Pro S range has never been officially approved by Porsche, although it is in line with Porsche requirements and is potentially approvable"

I have also been told that esters swell the seals in engines and PAOs shrink them. This is perhaps one of the reasons why Mobil 1 is known to have had small amounts of esters added to it in the past (don't know if it still has them or not). My engine seems to leak an awful lot at the cam covers & timing chain covers (currently filled with M1, which has a relatively low viscosity), despite attention here.

Bottom line: I'll be going for Silkolene Pro-S 10W-50 next time. The handbook for my car specifically states that a 10W weighted oil is recommended. This is only my humble and ignorant opinion, but I do now feel that I'll be using the best oil possible (IMHO).

Hope this doesn't cause any trouble, just want to contribute something new to the debate.

Roddy []

 

[angry]

I have used that Silkoline and it was ok.
I now use the Fuchs,as it is still good quality and a lot cheaper than Silkoline.
But i do change my oil every 4-5000 miles,because of the type of driving i do.
It still drains out with some colour in it,so thats not bad degradation in my eyes.
Dan

 

[John Maddox]

I wouldn't put 10-50 in mine, no way.

 

[eddieterry]

Very interesting Roddy - I agree with all you say about Esters and using 10W does seem a good idea but do think that 50 is a bit high. Have you thought of the Motul 8100 x-cess 5W40 which seems to meet all the spec without having to use a non Ester such as Mobil 1 and if not why have you gone for Silkolene instead, which I know has a great following on Pistonhead 993 owners and is meant to be very good but is not approved (would be very interested to know as I have always been told to use a semi-synthetic such as Magnatec for similar reasons but think that an Ester full synthetic should do the job - I think the independants that I talked to probably were just worried about Mobil 1 but did not like to name the product) Would be very interested in your reasons as you have obviously gone into it in depth. Eddie

 

[Guest]

ORIGINAL: MoC2S

Stirrer !!

Interesting that they didn't recommend the Fuchs Porsche approved oil .. Oh, and a 10W will never be approved on the current Porsche requirements

I wonder how many horsepower you'll lose going to an SAE 50 .. ? .. []

And whether the esters will keep your lifters pumped up ... ? .. [:-]

cheers, Maurice []

well Pro-S 5W-40 then! [8D]

 

[Guards Red]

Hi Roddy, I've had it in my engine for a number of years now and supply it to my local OPC for them to install. Had no problems with loss of power and have not had any issue with the lifters. Used my car every day over winter and had no clatter or any issue. Mostly dried up my engine too.

People say a 10 weight oil is wrong but we both know it was in the handbook at the time of production. Why would it suddenly not be suitable? I buy the best I can and was a firm believer in Mobil One until it started my engine leaking. I was told by many engine builders not to use it on an older engine. Mine was leaking oil which really made me unhappy with the car, not what you expect from a Porsche and I considered having it rebuilt. The guys I consulted said I should just change oils and it worked. If yours leaks, go with 10/50. Might not fully dry it up but it will work fine. I don't rev it above 2000 rpm for 10 minutes or so and not over 3000 till it's warmed up but I did that before the Silkolene on the Mobil one.

Each to his own though.

Regards
GR

 

[ubertub]

ORIGINAL: angry
It still drains out with some colour in it,so thats not bad degradation in my eyes.
Dan

Does this mean the detergents are not working and the crud is left in the engine, or your engine is spotlessly clean?
mik

 

[sue11sam]

Well , I am going to continue with the Motul, I agree that 10W50 is high , but I suppose if your engine is leaking like a seive it may help ' and if the motor is high mileage it should reduce the leaks , if the leaks are cam cover you should be able to reduce them by other means without chucking in a few gallons of treakle . As I have said elsewhere I have used the Motul for well over 2 years now and found it brilliant in all respects . There are thousands of 911's running around in France on the Motul without any adverse comment in the 'Porsche' press , like Flat -Six for example[]

ORIGINAL: eddieterry

Very interesting Roddy - I agree with all you say about Esters and using 10W does seem a good idea but do think that 50 is a bit high. Have you thought of the Motul 8100 x-cess 5W40 which seems to meet all the spec without having to use a non Ester such as Mobil 1 and if not why have you gone for Silkolene instead, which I know has a great following on Pistonhead 993 owners and is meant to be very good but is not approved (would be very interested to know as I have always been told to use a semi-synthetic such as Magnatec for similar reasons but think that an Ester full synthetic should do the job - I think the independants that I talked to probably were just worried about Mobil 1 but did not like to name the product) Would be very interested in your reasons as you have obviously gone into it in depth. Eddie

 

[sue11sam]

Hi Maurice , yes if you recall I run on Motul 8100 x-cess 5W40 , happy motor , but my engine is only k74 killometres , so it did not leak anyway []

ORIGINAL: MoC2S

ORIGINAL: sue11sam

Well , I am going to continue with the Motul

Can you specify which Motul ?? There are two variants Porsche approved, the ones publicised as 'Ester' oils are not .. eg 300V ..

cheers, Maurice [:-]

 

[Andy B Aces High]

Is the thread on oils going to start all over again !!! The one I started stretched to 61 replies and got a mention by Maurice in the latest Porsche Post.

I went with Sue11Sam's recomendation and used the Motul 8100 Xcess 5W40. It is on the approved list by Porsche and was recommended by Opie Oils who I purchased from. Cant give any feed back yet on any improvements to leaks as it hasn't been in long enough and I have changed the lower left cam cover which was my main problem leak anyway.

Andy B.

 

[eddieterry]

How bad is the leak ? If it is bad it may be an idea to use a very slighly higher viscosity oil, or if it is a seal you really need an Ester based oil to have any effect on swelling seals etc. The Motul X-cess is not ester based, if you want one of these then look at the Motul 300v and the Silkolene Pro S which are both Ester based and are reported to be as good as it gets but for some reason are not Porsche appoved (not sure why this is but then commercial considerations probably to feature in this area). Eddie

 

[38F3E1]

ORIGINAL: eddieterry

The Motul X-cess is not ester based

Interesting that the one Motul approved is not ester based. Are there any ester based oils on the approved list? This could be a long thread ...

:- D

Ian

 

[silver7]

is castrol edge 10w/60 approved for a 993 rs ? that is what JZmachtech recommend for a track based car? thanks

 

[sue11sam]

Just to be absolutely clear , my sugestion of the Motul x -cess8100 5W40 is for ROAD use only I do not know how it will fare in a 993 for track use , you will possibly wish to investigate further if your bias is towards high track use, but for the road , great stuff IMHO[]

ORIGINAL: silver7

is castrol edge 10w/60 approved for a 993 rs ? that is what JZmachtech recommend for a track based car? thanks

 

[Guest]

My 993 handbook from 1994 states the following:

"for winter and summer:

below -20 deg C: 5W-30, 5W-40, 5W50; above -20 deg C: 10W-30, 10W-40, 10W-50

for summer: 15W-40, 15W-50, 20W-40, 20W-50"

It's pretty fundamental that car manufacturers should advise on oils with a suitable weighting that covers all temperature scenarios in a given global region/continent. Therefore as an example, for Europe, where temperatures can drop below 20 deg C in some parts[/i], if a manufacturer recommended a 10W oil, this might not be ideal. Therefore, they keep it simple for us folks and just recommend a 5W or 0W oil across the World. I believe the handbook gives us more information however, and we can use this if we choose.

I believe that there is nothing wrong with putting Silkolene Pro-S 10W-50 in my car. Indeed, my handbook states that I can do this, as above. When did we last have a temperature of minus 20 deg C or lower in the UK?

As you can see in my post above, esters provide superb protection at engine start-up, so I'm not worried about the 10W weight in a UK winter.

Also, on the ZDDP (zinc/phorphorous) debate, it's interesting what Mobil say on their website about this:

"The active ingredient that you are talking about is phosphorus which is added thru a component called ZDDP. For products that meet the new ILSAC GF-4 specification the phosphorus levels for the oil must be less than 800 ppm phosphorus. The ILSAC level for phosphorus has been reduced to protect the catalytic converter and other emission protection equipment. The engine manufacturers are confident that this level of phosphorus will protect both new and older engines. However, there are Mobil 1 products which have a higher level of phosphorus (phos) and can be used in engines in racing or high performance applications[/i]"

I'm somewhat surprised by this statement. I would have expected Mobil to thoroughly endorse the anti-wear properties of all their oils that now have lower ZDDP levels, in this statement themselves, but instead, we get a reference to manufacturers being happy with the situation and some Mobil oils with higher ZDDP levels that you can choose if you want.

Make your own conclusions from all this.

Sorry Maurice, but I stand by my humble personal decision to move to an ester-based oil and believe that I am not stirring, but instead have justifiable reasons. Will let you know when my engine goes for a rebuild, or alternatively, when it gets to 200,000 without being opened up! This oil debate's a good thing, keeps me out of trouble anyway! [8D]

Regards
Roddy

 

[eddieterry]

I think you are going the correct way Roddy as Silkolene Pro S 5w-40 is a true ester based oil and will encourage seals to swell, however pao based oils encourage seals to shrink, in oils where the ester is blended with pao they tend to cancel each other out. Mobil 1 0w-40 and 15w-50 are pao based and I am told often leaks are associated with these oils. IMHO Porsche approval does not matter, as this particular oil far exceeds any Porsche specs. Everyone seems to have there own take on this subject but it is always interesting to hear peoples reasons - Eddie

 

[Guest]

Thanks Eddie and GR. I'll stop ranting from my soapbox now on this subject, said my bit and others have their own very respectable opinions.

Roddy []

 

[burrow01]

ORIGINAL: MoC2S


Every garage / pub expert propagates their own oil myths, but as far as I am concerned, I make people aware of the factory list of approved oils. The rest is up to you, but just don't ever complain 'nobody told me' !! .. [8|]

cheers, Maurice []

Given the amount of posts whenever anyone mentions oil and 993 in the same sentence, I don't think we could ever claim to be uninformed []

Pete (just taken delivery of 15ltrs of Silkolene Pro S 5W/40......)

 

[angry]

ORIGINAL: ubertub

ORIGINAL: angry
It still drains out with some colour in it,so thats not bad degradation in my eyes.
Dan

Does this mean the detergents are not working and the crud is left in the engine, or your engine is spotlessly clean?
mik

Dunno,90% of the time you can wipe your finger round the inside of the exhaust tips and not get a single trace of dirt on your finger.
Also when ive looked down the inlet manifold the base of the valves are crystal clean.
It also past the cat test with no cat fitted.
It does run very well ,quiet/strong and returns excellent mpg,not bad for 110000 miles.
Dan