Popping over here from the 911 Forum, I have two, as I have just purchased a 1964 356 and have a oil question. I use high zinc oils in my Messerschmidt and Isetta and plan to do so in the 356. My question is to oil weight as I have done a lot of reading recently and am getting mixed messages. Here on the Texas Gulf coast we run temperatures basically from the 40F-100F Winter to Summer. Would you recommend a 10W30 or a 20W50 weight? The reason I am in a quandary is that the 356 air cooled engine is so much larger than the 9hp and 12hp I am used to working on. Thanks

 

When located is SoCal, always used straight 30 wt Castrol and changed every 3K miles.

 

Apologize if I'm sounding rude, but why not use search? This is one of the mostly used question in all auto forums
and there are multiple of replies from people who know what they say and people who just want to say something
with the total clueless about the subject.

I strongly recommend that you join 356Registry, there are a lot of knowledge and people who share their wisdom.
Here are couple of pages from there about the oil question:

https://forum.porsche356registry.org...hat+oil+weight

 

I will join the registry today. The pages you highlighted recommend straight 30 weight, 10W30, 15W40, 20W50, no weight recommendation but it must contain added ZDDP and no weight recommendation but it must be oil used for diesel engines. There is also a lot of arguement over whether ZDDP is necessary for plain daily use and if some oils cause a “”wax” buildup in engines. After pages and pages the question is never answered. See my quandary?

I’ve ended up and read a lot of Registry pages Googling questions so far and there is a lot of posturing and one upmanship going on. Thousands of words being written when a simple sentence would answer the OP’s question. I’ll flip for the $55 bucks for a years membership and give it a longer try.

 

Hmm, I've asked a lot of questions on 356registry forum and always got an answer without any "posturing".
Without wanting to start an argument, aren't you also doing this As I suggested earlier, use search and if you're still in doubt, may I suggest that you check a bit deeper into this and then you can make your decision based on your studied facts,
instead of someone elses. Or at least so much that you have a basic understanding what the discussion is instead of trying to find a ready solution without any work?

You could start with these and I can assure you that the sky is the limit in tribology (I just randomly picked these examples)
https://www.valvolineglobal.com/en-ksa/understanding-oil-standards-acea-specifications/#:~:text=ACEA%20divides%20oils%20into%20three,SAPS%20and%20mid%2DSAPS%20 oils.
https://www.api.org/products-and-services/engine-oil/eolcs-categories-and-classifications/oil-categories#tab-gasoline
https://bobistheoilguy.com/forums/th...chanism.18554/

Even you might now accuse me for rambling, selecting correct oil in engines is quite critical, a 356 is not very picky, it basically need "only" the ZPPD, but using wrong oil in a modern
engine can be costly. The ZPPD is not so good for catalysators, so modern engines are designed so they don't need ZPPD. An extremely simplified reason just to give you an idea.
Shortly; oils are not always backwards compatible.

 

Thanks for the help.
So lets keep it simple. What oil do you use in your 356? 😊

PS-I use a higher zinc oil in my Messerschmidt KR 200 and BMW Isetta because club members have recommend it on their forums and also in my Ford Model T’s and Ford Model A with flat tappets though these engines are run at much slower rpms.

 

Valvoline VR1 20W-50 also in my ’85 911.
Porsche has changed their viscosity recommendation
for aircooled, they specify now 20W-50.
Nice cars you have.

 

Thank you for being specific. My two 911’s and the 356sc I’ll be picking up this next week. They keep me busy and out of trouble……😊