Oil?

[Greg944]

Hi guys,

What are people using or engine oil here in Oz? The cr is S2.

The previous owner o my car was using Mobil1 15-W40, but that's no longer an option.

Cheers

Greg

[T-Man]

Why isn't the Mobil-1 an option Greg. Is it the grade you can't get? 15/50 is available, but hard to come by.

Swepco is readily available in Australia. Very popular amongst enthusiasts.

[Greg944]

Theo,

Was told the grade was no longer available!?

This is my first Porsche, the last thing I want to do is cock it up with a bad oil choice.

The owners manual calls for 20-W50, everyone else seems to be using something else, especially on Pelican, 944online etc (let's not get into synthetic vs dinosaur oil)!

A lot of people are also saying Mobil1 is over priced and doesn't offer anything over say Castrol or Penrite...

Greg

[JustJames]

Greg, I'll keep this reply as brief as humanly possible.

There are two variables that are relevant when choosing an oil:

1. Viscosity. How gooey/watery is the oil?

2. API rating. This will be somewhere on the container, and will be SL, SM or S-something else. Further up the alphabet means better.

Everything else is marketing.

[J.J.]

so James is the ZDDP content not important for a 3.2 Carrera? or is that just marketing

[JustJames]

so James is the ZDDP content not important for a 3.2 Carrera? or is that just marketing

No embarrassed smiley.

ZDDP content is important for engines that require it, and having owned old English cars I am aware of the importance of ZDDP.

I found this in a discussion on the Pelican Parts forum:

"The "Father of Mobil 1" presented at the Lime Rock Porscheplatz this Summer

He said: The "SM" specification that lowers the levels of ZDDP, only apply to the low viscosity classes of oils. Such as -30 and below. And these reduced level were really targeted to new cars, because ZDDP can cause the elements in the catalytic converters to break down faster, thus hurting the emissions. Plus those cars are now running thin grades for efficiency (5W and 0W grades.) Hence -30 and below are subject to the reduce levels.

In essence, he confirmed all SM oils, -40 and up should have higher levels of ZDDP. "

You can read the full thread here:

http://forums.pelicanparts.com/porsche-911-technical-forum/432060-zddp-levels-really-important-seriously.html

[T-Man]

And if you are looking at killing a weekend over the subject have a look..........................

http://forums.pelicanparts.com/porsche-911-technical-forum/367300-ultimate-motor-oil-thread-why-we-hate-cj4-sm-oils.html

[wasserkuhl]

I would be inclined to subscribe to the thread that Theo has posted up. Charles Navarro knows what he's talking about.

Oil is a can of worms as James has indicated above(!), much like Religion.

I am sticking to shorter drain intervals and Mineral "ZDDP Rich" content Oils in both my pre-cat Porsches.

Never had a major failure and alot of so called experts totally dis-agree and recommend Synthetic all the way..............

[VS GTS]

Did you end up deciding what oil you're running with ?

I am the Swepco agent for Sydney but would be happy to help where I can.

[T-Man]

Mobil-1

[wasserkuhl]

Mobil-1

What weight? 10w 40?

[T-Man]

What weight? 10w 40?

Spot on - 10w/40 Synthetic

[9fan]

Hi Theo,

What good oil do I use ?

WD 40 or BUNDY - will make anything good !

Mobile super 3000 5W-40 less expensive than M 1 but Fully Sick(Synthetic) !

Cheers,Mark.

[wasserkuhl]

Hi Theo,

What good oil do I use ?

WD 40 or BUNDY - will make anything good !

Mobile super 3000 5W-40 less expensive than M 1 but Fully Sick(Synthetic) !

Cheers,Mark.

Mark,

do you use a Mobil 5W - 40 in your Transaxle cars? I was using a 10W 60 in my CS and my prior 944S2.

[9fan]

Now using this in CS, Not sure previously - may have used Mobil 15W-40 in S2 but synthetic.

They change their products over time and the M 3000 is the level down from M 1 so more cost effective quality (buy when discounted) for more regular oil changes.

[Buchanan Automotive]

Some basic in the field observations over the last 35 or so years working on last century Porsche cars .

First of all }

Did we see worn-out cam lobes + hydraulic lifter faces, badly worn camchain sprockets( twin cam) , crankshaft thrustbearing wear , unusual excessive cylinder to piston wear , way too early valve guide wear in last century Porsche engines in cars sold to the public from the 1970's to the around 15 years or so ago and these cars just running on a decent quality 20w-50 and the oil changed say once a year or 10,000Kms ?

Answer = No

In fact the wear rate was so low( even a little wear) , we often thought Porsche engines would never wear out , in this I am talking about 944 2.5L , 944S 2.5L , 951 , 944S2 , 928 ( all ) , 911 ( all )

We even have some customers with the somewhat notorious 2.5L 944S ( twin cam 16V ) with well over 400,000 Kms with no wear at all with the cams or sprockets or even valve guides , the reason I mentioned that is because we took the head off the highest km customers 944S ( twin cam) in the last month ( first time ever ) , the cylinders were unmarked , no cam wear at all , no cam chain sprocket wear , even the valve guides were still in spec ( Ex ones only just ), this car just received new gaskets & seals ( old head gasket was rotted with old age) , new timing chain ( between cams & slipper guides).

This 944S I have known since new & has only ever been on a good quality 20w-50

Is this the same for last century Porsche's that have been on a low viscosity & low ZDDP so called synthetic oil , meaning Low Oil Film Strength Oil ?

Answer = No way in the world , the usual here is massive wear of the above components mentioned , often in less than 60,000Kms on switching , depending on how low the oil film strength is of the so called synthetic oil ( these are usually hydro-cracked crude oil & advertised as synthetic which is legal )

But Why ?

Answer = Emperor's New Clothes , meaning humans just love buying something that's hyped up without really knowing just what they have purchased

Did you notice the components mentioned above ( cam lobes etc ) all these components rely on oil film strength alone , meaning no oil pressure

How do we increase oil film strength in engine oils on this planet in this universe ?

Answer = A) Increase oil viscosity say from a 5w-40 to a 20w-50 ( with both oil with the same levels of ZDDP ) which often they do not

Increase ZDDP

If you take one away you decrease oil film strength

If you take both away you very very much reduce oil film strength( very rapid cam wear etc)

Now we go onto Vii's ( viscosity index improver's ) , these little gems are added to the oil to stretch out its intended viscosity , plus remember the more Vii's the greater the stretch & they start with the lowest number , so if its a 5w-50 , then its just a 5weight oil with a heap of Vii's added & remember Vii's are not a lubricant in their own right they are just an additive .

So if you keep the numbers a little tighter the less Vii's are needed ( 20w-50 ) for example

Oil companies have had a lot of issues with Vii's over the years , because if left too long in the sump , these little additives help accelerate turning a percentage of the oil into little hard little granules that block up the oil intake gauze = no oil pressure because of blocked oil intake ( seen when oil change interval is left too long

And yes there has been some good inroads into reducing this with some clever chemistry over the last few years but the fact remains there is a lot of Vii's that are not a lubricant in their own right , just more of an additive

Now we go onto oil pressure , measured with a workshop oil pressure gauge , if you install a 5w-50 into say a 968 & get it up to high core temp ( not rad temp ) engine core temp ( oil temp say 95 + deg cel) you will get a given idle oil pressure ( say 1.5bar )

Then you drain the oil & install a 20w-50 oil & repeat the test , you will see not 1.5bar but at least .4 of a bar higher ( 1.9 bar )

The reason is the 5w-50 is not really a 50 its just a rounding off of a number , so a 5w-50 will actually be closer to a 5w-45 , as the 5w-50 gets older ( many heat cycles later) it drops even further

Same goes for the 20w-50 , but with less Vii's its more closer to the 50 ( say 20w-49 )

So what I am getting at is the cold start furthy is more of a myth in these last century Porsche engines , the real wear is engine hot where oil film strength is very criticle ( metal to metal contact) , particularly with these high loaded flat tappet designed last century Porsche engines

The other thing of interest is oil to the top end ( engine cold ) and cranking , try it you're self as I have done

944S2 / 968 , twin cam camcover off , engine oil 20w-50 ( as per owners manual ) ambient temp 7 deg cel ( mid winter first thing in morning)

First thing noticed ( before cranking) is that cam lobes are still covered with a film of oil , same goes for the lifter faces , yet the engine has not run for several days ( this is much less the case for a 0w-40 which is only natural because its extremely thin hot)

Crank engine = oil spraying everywhere before engine even fires up( what a mess) , so much for the Molasses comment which only comes from people who do not know , they just guess or just spread non truths for whatever agenda ( maybe that are a rep for that oil company ?)

Last but not least , the 944/951/968 series oil pressure relief valve opens around 7+ bar of pressure , so like the humble 924 Porsche which had a 0-10 bar oil pressure gauge , so should the 944951/968 as well , because the max 5 bar reading is not the max at all, its just showing part of the oil pressure being made , which leads me to the conrod bearings , No 2 conrod bearing in the 944 / 951 / 968 are at risk to damage from low oil pressure , the simplest way to get around this issue is to go as high as viscosity ( high oil pressure) to reduce / stop the oil bubbles forming in the pressure circuit ,that's why we do not loose engines to this issue , but on low vis oil with high oil temp its a problem at full power with these last century Porsche engines

But like I said , no complaints from me , the work just keeps pouring in from the use of low vis , low oil film strength oils in last century Porsche's, meaning viscosities that are out of the range that is printed by Porsche in the owners manual in the multi grade" look at me section" ( I hope it continues ) at least no one can say , we didn't warn owners of this

Regards

Bruce Buchanan

Buchanan Automotive

[Greg944]

Bruce,

Thanks for that information. Will be chasing some new oil soon and the next question is in regards to filters:

Mahle, OEM, or ???

Cheers

Greg

[Buchanan Automotive]

Hi Greg , we have been using Mahle ( made in Austria) for decades , excellent quality & never had an issue with this brand

Regards

Bruce

[Chris-p]

Thanks Bruce, thats a really informative post. I have for quite a while been struggling with why they have been using 0w and 5w oils in Australia. just makes no sense to me....

By the way welcome to the forum and keep the informative posts coming.

cheers

Chris

[Buchanan Automotive]

Thanks Chris

Regards

Bruce

[wasserkuhl]

Bruce is a Gun. Listen to everything he says.

Sean, is also a gun.

GUNS.

[OzJustin]

Only just stumbled across this thread.

Some very insightful info from Bruce Buchanan,  I had read a little about the ZDDP issue in one of the Rennlist threads but your post is far more concise.  Thanks for sharing the important details