Kevin

Paul do not run 15w-50 with your Vario Cam engine.. I am bringing Mobil 1 5W-50 over the border..

Well I see more Porsche bearing than most people on this forum and see more KKK turbocharger failures than probably anyone in the world. I see what the oil is doing and what it isn't doing. The thrust system in turbochargers has very extreme surface loading.

Read>> Synthetic oils are a turbocharged engines best friend.. Google Mobil 1's VTwin tech sheet and read it.. If you guys are sold on zinc additives VTwin has them.

WHB Porsche

Kev - what would you recommend for a yearly driven, perhaps 1-2 a year tracked, car in the NE? I feel like 20w-50 is too heavy for winter.

DJF1

I asked you a few questions BB on my post on the 993 thread but did not get any answer. While I respect what you guys are doing and your empirical experiences the fact is I have a really hard time getting on the bandwagon of the mineral oils and dismissing expert advise and Porsche's recommendations. Furthermore as I said on my post on the 993 board, there is at least one mechanic that I know that has more experience than many mechanics combined, that swears on Mobil 1 15-50 for my aircooled engine. I'm sure that he is not the only one as it is evident on this thread.
So the million dollar question is: Should we believe 3 people, with at least one selling the products they preach , or believe the factory, oil engineers like Doug and other Porsche mechanics who would not touch mineral oils and swear by the Mobil 1???

Kevin

Charlie, if you are driving your car year round, I assume that you will change the oil twice a year. Run a lighter oil in the winter and the VTwin when the weather warms up, and on the track..

JET951

Hi DJF1 , remember I am not trying to sell you to a particular brand or anything else for that matter only be aware that those who do work on Porsche cars week in and week out do get to see what the consumers do not and the amazing thing is for me at least is in Sydney there is another much larger Porsche specialist that specializes in track oriented 996GT3's and 997GT3's and what even amazed me is that I found out last November that they switched over to Redline oils more than a year before because of what they described as excessive engine wear and they are in their words" are now much more comfortable with little or no wear now with redline" (their words not mine ) and like I mostly see very few Porsche specialists see very little merrit in the trouble and strife in advertising this simple change .
regards .BB.

DJF1

BB. I did not imply that you are trying to sell me any type of oil. However your reference clearly points to the bandwagon for the mineral stuff. As I said I do not doubt your field experience, my issue is that top mechanics point equally to Mobil 1 15-50 for my aircooled 993 engine. Furthermore GT3's in general have different lubrication needs than my engine so what is good for these engines may not be necessarily good for mine. Finally the factory raced the 964/993 engines solely with Mobil 1 and factory filled our engines with Mobil 1. Clearly back then the formulation may have been "right" ,on the same token I dont see them racing with "brad pen" or "swepco" back then or now!
Oil Engineers who certainly know much more than you and me, like Doug, also understand much better the chemistry as a whole of the new formulations. I cannot even comprehend how these chemicals react with each other and I'm called to believe that the ZDDP is the sole savior of my engine's health... Interestingly this site of another "expert" :http://www.carbibles.com/engineoil_bible.html says about using diesel oil and I quote:
. Please read here about the engine loosing compression!!!

Also read about mineral oils, synthetics, ZDDP's etc...

So pardon me if I dont choose to jump on the band wagon and stick with what I'm told by people I trust...

JET951

Hi Danny,
our bandwagon is not so much to do with mineral oils at all. we have been stating our experience with such oil in previous posts. for later vehicles we use specified weight synthetic oils. we have an issue with 2 things, viscosity for the year and compatibility with the vehicle. We have no issue with Doug at all, we simply do not agree that it is a good idea to be running a diesel oil in the porsche from this era backwards. we have seen papers relating to the effects of high detergents on ZDDP within oils.
infact here is one
http://www.apmaths.uwo.ca/~mmuser/Papers/TL05.pdf

it states on page 8,
Fully formulated engine oils contain additives other
than ZDDPs, such as detergents, dispersants and fric-
tion modifiers. It is imperative to understand the effect
of these additives on the efficacy of ZDDP. Dispersants
alter the solution chemisty of ZDDPs [50,51], while fric-
tion modifiers have little effect on the AW properties of
the films [52]. Detergents, on the other hand, alter the
chemical composition of the films, affecting AW per-
formance [45,53,54]. Common detergents contain cal-
cium ions, which are incorporated into the ZP film by
replacing Zn. On iron-based materials, this increases
wear compared to that observed when ZDDP is used
alone [45,53].

iron based materials include, cams/crank/rockers.
Sean

JET951

Good point Danny , except for one small problem , the high levels of detergents in diesel oils are there solely for the purpose of using in diesel engines .
To see for yourself ,google in "ZDDP" . on the first page you will see the scientific paper }
Interpretation of experiments on ZDDP anti wear films through... by NJ Mosey.(4th one down from the top )
First page it states :Quote:
Seventy years after their development , ZDDP remain a key anti wear (AW) additive in commercial lubricants used in automotive applications. This is particularly remarkable considering that significant efforts have been made over the last decade to replace ZDDP in engine oils .The rational design of the new (AW) additives has been hindered by the absence of a basic understanding of the functionality of ZDDP .
In fact until very recently no single theory existed that could convincingly explain the" abundance" of experimental observations regarding these additives. end of Quote .
Danny it gets even better or worse if you know what I mean ,
page 8 heading } Effects of Detergents
Quote > Fully formulated engine oils contain additives other than ZDDP, such as detergents, dispersant's and friction modifiers. It is imperative to understand the effect of these additives on the efficacy of ZDDP while friction modifiers have little effect on the AW performance . Common detergents contain calcium ions , which are incorporated into ZP film by replacing Zn.
On iron based materials , this increases wear compared to that observed when ZDDP is used alone.
end of Quote.
so in other words the much higher levels of detergent will a effect the way ZDDP works , remember that 993 and 964 models have iron based cams rockers/ cam followers , sam chain sprockets , etc etc .
Regards BB.

WHB Porsche

One last question and then I'll stop, and I do appreciate all the advice and time spent on this subject.

The car is only driven 1-2000 miles per year, so if I had to only change oil once per year, what should I use? 5w-50? I assume that allows for low abuse on cold start in the winter while adding protection by the heaviness in the summer? Would I be okay with a 5w-40 or 0w-40 in the summer? I'm rather bad at making a decision when there are so many options and varying opinions from experts I trust and would prefer an "end-all, be-all" kind of answer, if there is one.

OldGuy

so kevin what you suggest for our vario cam motors?

Kevin

Paul, without a doubt 5w-50 Mobil 1.. It's tough to get, but it can be had.. Google Canadian tire..

Charlie, find some 5w-50 from north of the border. You can also run Motul 300V However, if you are only putting 1 to 2K on your car are you really driving it in the winter???? Or just starting it and moving it around the garage (smile)..

WHB Porsche

Thanks for the advice Kevin. I'll have to try to source some.

Charles Navarro

Another tidbit I forgot about - the VW 505.01 spec oil for turbo diesel engines (like the V10 5.0L TDI), is a semi-synthetic oil, which is still overwhelmingly dino oil (only about 10% syn when I looked into one particular oil), and that holds up just fine. It's only with extended drains now that they are going fully synthetic. The Swepco too is the best 15w40 diesel oil out there, and granted most diesels are turbo too, and I've never heard of or seen a problem with non-synthetic 15w40s in this application. The big rig/fleet repair shop next door to use doesn't use synthetic anything except for Delvac 1 gear lube.

I think what is paramount is that if you drive the car hard, regardless of what oil is used, that you let the engine idle and the turbos cool off first before shutting it down, like VW says in the owner's manual, so that the oil doesn't coke up from siting in a blisteringly red hot turbo :-)

Have a great weekend guys!

breale01

A Canadian newbie with a spinning head here. Here's my dilemma....

-Relatively new owner (driven approx 1500 mi/2400 km) of a 1990 911 C2 with no perceptible leaks or oil burn. Current oil 20W50.
-I would like to stick to Porsches latest recommendations per their TSB, yet I am very hesitent to put in a 5W viscosity, since I don't want to trigger leaks. However, I trust Porsche engineers in regards to proper lubrication being achieved at start-up with a 5W....(yes?)

A question Doug: Can you clarify what you mean in your quote above? Isn't it Porsche Approved only if the oil is exactly what is in their TSB, including brand AND viscosity?

Lastly, what does all this mean with respect to the Owner's Manual recommendations? Does the latest TSB of Approved Oils completely supersede the Owner's Manual? Why then aren't the new oil recommendations readily available to the general Porsche public who may not read enthusiast forums?

Spinning in Canada.

Charles Navarro

Stick to using a 20w50 with the proper API rating (not SM). Back a few years ago, when I purchased my 91 c4 cab, it had been run with GTX 20w50 it's entire life. Having the old m1 0w40 (prior to reformulation) around, I put that in. The engine was bone dry prior and with the m1, started leaking from every oriface. Even switching to a non-synthetic didn't stop the leaks. After a minor reseal (valve covers, oil returns, cam towers), it doesn't leak anymore. I've run through it, for testing purposes, various non-synthetics, semi, and full synthetics, and it's nice and dry.

Porsche's approved oils make sense for the water cooled, newer cars, with more sensible drain intervals than they even recommend. I, along with many engine builders and independent shops, agree that these approved oils are not what are best for the older aircooled engines. Even an '04 recommends an SH/SJ, according to the owner's manual...