Jay Gratton

I agree with Matty on this part. Run what Porsche tells you to run.

Mike Murphy

Yeah, in the motorcycle and lawn engines, but what are your thoughts about using Amsoil in the air-cooled Porsche? I run Amsoil 10w40 in my V-twin 1100 Honda cruiser (HD rip-off) and I really like it. I run Shell Rotella T 15w40 in the 88 911.

Al Cody

I am a Castrol GTX 20-50 fan as well.
I also add two tins of Moly Slip E to help with friction.

Graufuchs

Interesting I thought additives were ALLWAYS bad?

Steve Weiner-Rennsport Systems

With the exception of GM's EOS or Torco's MPZ , thats true.

Charles Navarro

Ok, I'm to the point that I am going to sit down and write Porsche. I have enough SAE papers that document the direct relationship of ZDP to valvetrain wear proportional to valve spring pressure. I'm sure that Porsche's recommendation for oil for their water cooled, dohc four valve per head engines is fine, since the valves are 6mm stemmed tiny little valves with itty bitty springs you can compress with your fingers. An aircooled engine with sohc and two larger, heavier valves, with bigger higher spring rates requires more anti-wear additives. I have a stack of documents from various sources, many being oems and those developing the testing sequences themselves that document this. My recommendation stands, if you use a Porsche approved oil IMHO it is not best for your aircooled engine. That's why Steve, myself, and others have either switched to other oils or have added EOS (within limits) to the factory approved oils for the required protection.

1986951

Charles, is the GM EOS available thru GM dealers, or can you buy it at your FLAPS?
And how much per 12 quarts of oil do you recommend?
This is uncharted waters for me... back in "the day", I just dumped in the Shell or Castrol and drove away happily knowing that if I changed the stuff regularly, no harm would come to "My Precious"...
it was nice to live in a more naive, simpler world!!!
Thanks in advance!

Charles Navarro

It all depends on your starting oil; for a 993 or earlier aircooled Porsche, you really should have .12% or 1200 ppm. When adding EOS, I personally think that if you have to add more than one bottle (which would raise 12 quarts of oil by roughly 200ppm Zn and P), that you need to choose a different oil. In the case of Mobil 1 0w40, which is a Porsche recommended oil and the factory fill in new Porsches, I would add just one bottle of EOS.

GM EOS is available only through a GM dealership, however you may find it online from various sources. I just got it from my local dealership and paid somewhere around $6/bottle, but I had to buy a whole case since they didn't stock it and didn't want the extra.

mkimber

Valvoline VR1 Racing 20w 50 for my '87 Carrera. Castrol GTX 20w 50 if I can't find the Valvoline.

Steve Weiner-Rennsport Systems

First off, I’d like to say that I agree wholeheartedly with Charles on this and I respect and admire his amazing efforts to enlighten the Porsche community about this critical topic. That being said, I do not delude myself that Porsche A.G. (or anyone else) is likely to truly listen to their experiences and feedback and consider everything with an open mind. Human beings are simply not wired that way when credibility is heavily outweighed by corporate appearances and legions of heavily degreed professionals against individuals who only offer real-world practical experiences.

A word about oils (and Porsche’s) is in order,……

Discussing oils with fellow automobile enthusiasts is akin with debating one’s political or religious convictions with friends & acquaintances and these conversations oftentimes take on a confrontational and defensive tone, neither of which becomes constructive. No matter whom you ask about this subject, everyone will express their opinion based on experience, hearsay, or various publications.

The one thing really lacking in these conversations (oral, or the written word) is context. This is critically important to establish relevance and credibility when deciding what bits of information will be the most useful and I see little context when individuals or businesses make specific recommendations for engine lubricants. As I’ve mentioned before, “Whats good for the goose, isn’t necessarily good for the gander” and this means oil recommendations are not the same for ALL engines. Air-cooled, water-cooled engines, and racing engines all make different demands on their lubricants. Further, each engine’s configuration and design varies by each manufacturer and some will not be adversely affected by the reformulated oils that are now in use.

When listening or reading about the various choices of oils to use in your Porsche (or other cars), its very important to ensure that the recommendations are offered with YOUR best long-term interests being the only priority. Many things have changed in this regard at various manufacturers and they do not always hold altruistic reasons for their recommendations anymore. Back in the ‘70’s and ‘80’s, most automakers were unaffected by marketplace forces and made their oil recommendations with their owners/customers in mind. Back then, Porsche’s oil recommendations were rightfully taken as “gospel”.

This is the not case today where parts sales now comprise a FAR larger part of corporate profit centers (we see this in ever-increasing aggressive parts pricing) and therefore maintaining the long life of their products contains a potential conflict of interest.

Choosing the right oil should not cause anyone grief or undue stress as there are many good products available right now. My recommendation is to talk to your mechanic or anyone who rebuilds engines for a living since these are the folks who see the long-term effects and should have YOUR interests at heart.

Graufuchs

Nicely written steve. Nicely studied by charles navarro......My hypothesis of what will happen once this letter is written, is that Porsche will take the letter and file it, and write back a nice letter thanking Mr.Navarro for his time and research and thats as far as it will go. One can only guess what "contracts" Porsche has with various companies ect. and unfortunately money over shadows the truth. Now Im not a conspiracy guy at all, but we all know its common buisness sense, buy low sell high. Thumbs up to you both for taking the time and thought into this matter. Now what oil should I use in my 87 Euro 3.2l ???

theiceman

Now what oil should I use in my 87 Euro 3.2l ??? [/QUOTE]

..you beat me to it ..

Steve Weiner-Rennsport Systems

fty:

There are several good oils that one can use in these engines. Here is a partial list of the ones we recommend (the ones we are currently using have an asterisk):

Swepco 306 15w-40 or 20w-50*
Brad-Penn 20w-50 racing oil*
Valvoline VR-1 (off-road) 20w-50*
Mobil 1 V-twin 20w-50*
Royal Purple MC oils


Now,.......One can use other oils as long as the ZDDP content is at, or above 1200 ppm. You can accomplish that by fortifying it with some EOS or Torco's MPZ. There are other oils but these are the ones we will use.

Needless to say, there is a lot more to the oil chemistry aspect so this is a grossly simplified answer to the question about what to use.

Charles Navarro

If you use the VR-1 "not-street-legal" oils from Valvoline, you just need to make sure not to go too long on it, as it's what I would consider a low detergent oil, having about half of the VR-1 found at Autozone, etc.

Like Steve said, there are lots of good oils to choose from. Just a few stand out as excellent for one reason or another like those he posted. I would say they are all excellent recommendations for an aircooled Porsche and I have personally used all the oils on the above list at one time or another over the past few years.

bgiere

My 3.2 does very well on Rotella 15w40 or Chevron Delo 15w40...These two oils have given me the least wear (confirmed by used oil analysis) for my usage. This car is street driven with a couple track days each year. Oil is changed once per year. For the race cars, we use Redline 10w40.