Oil for an air-cooled 911

[zray]

Originally Posted By: 901Memphis
Mobil 1 15w50


Excellent choice .

I've used this in all the 911's I've restored with zero ill effects

Z

 

[rsamerica]

Thanks everyone for the responses, I have some good ideas what to go with. The joe gibs racing dt40 and dt50 looks interesting, as well as mobil 1. The car will be mostly street driven, maybe a few track days, but thats about it.

 

[Garak]

My two cents is to follow Doug Hillary's suggestions.

 

[Shannow]

Originally Posted By: Garak
My two cents is to follow Doug Hillary's suggestions.


LOL, was just about to state that if I owned an aircooled anything, he'd be the first person that I'd listen to.

 

[Peter_M]

Actually Doug is the only BITOG'er that I have read his every post and in many ways I followed him here from a number of Porsche forums he used to frequent.

Isn't as creepy as it sounds I promise!

I actually read a lot of your posts Garak and Shannow too.

I would use Mobil 1 products as well but as you know Shannow they are horrendously expensive in Australia and consequently I've been interested in less expensive alternatives and simple and objective ways to identify those alternatives.

 

[UnclePeco]

If you are near Scranton pa, I love working on those old air cooled engines and have some parts from prior cars I need to get rid of. Let me know if you are interested.

 

[supercity]

Would people here feel comfortable using a C3 formulation that was 229.51 and A40 approved?

 

[sds911]

Peter

I'm not arguing with you. In fact Charles Navarro makes the same recommendation for the acea specs as you do. And states that a lower weight than 15w50 may be fine depending on ambient temps. Read the links I posted and you will find you and he are making similar recommendations.

A40 has served my 996 well for 75000 miles. I'm going with higher zddp oils (dt40, motul, etc) for the next 75k and there is nothing wrong with that since in fact the older formulations of Mobil 1 etc used to have those higher levels for decades. It's cheaper to replace a cat converter then a 20k Porsche engine.

For my Subaru I use whatever synthetic brand is available on sale from the big names and they all will work well with a 7500 oci, and my last Uoa with Mobil 1 ep was fine. You can see from my posts and UOAs that I'm not saying there is a best brand. In fact quite the opposite.

 

[dave1251]

Rotella 5W40.

 

[rsamerica]

Originally Posted By: UnclePeco
If you are near Scranton pa, I love working on those old air cooled engines and have some parts from prior cars I need to get rid of. Let me know if you are interested.


I'm about 30 miles north of Pittsburgh. Do you have anything interesting for 964 cars

 

[Peter_M]

Originally Posted By: sds911
Peter

I'm not arguing with you. In fact Charles Navarro makes the same recommendation for the acea specs as you do. And states that a lower weight than 15w50 may be fine depending on ambient temps. Read the links I posted and you will find you and he are making similar recommendations.

A40 has served my 996 well for 75000 miles. I'm going with higher zddp oils (dt40, motul, etc) for the next 75k and there is nothing wrong with that since in fact the older formulations of Mobil 1 etc used to have those higher levels for decades. It's cheaper to replace a cat converter then a 20k Porsche engine.



Hi SDS,
I apologise if my tone was perceived as argumentative, that was not my intention.

You raise one of the propositions that I just can't my head around. There seem to be a notion that there are specific brands of specific viscosities that will safeguard an engine from premature destruction and to use any other oils will guarantee damage.

For the cars we love it is widely espoused that high ZDDP and Xw-50 grade oils will save 911 cam lobes, thrust bearings in 928's, big end bearings in 944's and 928's, IMS bearings in M96's etc. I just can't accept that proposition particularly when the reasoning given relies on flawed logic and statistically insignificant and flawed data.


However I do agree that certain oil classifications like ACEA A3/B4 are likely to better for our particular engines and usage but I just don't think we can ever get to the point saying Brand X is better that Brand Y for the same oil classification. Similarly for a street driven 911, I can't see there is any data to support if a Xw-40 is better than a Xw-50 for longevity or vice versa.

In a nutshell, I just don't think there is a "magical" oil in the marketplace that will solve Porsche occasional examples of poor engineering design and practice.

With regard to your intentions with your 996, I can't see any disadvantage moving to a high ZDDP oil as recommended by LN Engineering for the same reasons discussed above.

I apologise again for my previous tone and hope we can keep the discussion going to allow us both to learn.

Regards

 

[Peter_M]

Originally Posted By: supercity
Would people here feel comfortable using a C3 formulation that was 229.51 and A40 approved?


Super,
Is there such a beast?

While C3 gives the required HTHS for our purposes, I would think the 229.5 and the C3 specs would be at odds with each other. Similarly with A40 and C3.

Happy to be corrected!

 

[Garak]

Originally Posted By: Shannow
LOL, was just about to state that if I owned an aircooled anything, he'd be the first person that I'd listen to.

And liquid cooled, and legacy, and modern....

 

[Clevy]

Originally Posted By: Doug Hillary
Hi,
rsamerica - Welcome to BITOG

The Factory Museum at Zuffenhausen used/uses a mineral 20W-50 in all of their Classic Museum vehicles - warmed to 80C prior to using revs or serious loading

When servicing the 356 and early 911s when living in Denmark in the 1960s we only used a mineral HD20 or HD30

Mobil recommend M1 0W40, M1 5W-50 or HM10W-40. M1 15W-50 is also a good choice

I used Delvac 1 5W-40 in my water-cooled 928s'



This is the right answer,written by a man who has intimate knowledge of/with Porsche.
If Doug writes it you can rest assured it will be canonized and added to the oil gospel.......
Just sayin

 

[Ramblejam]

Originally Posted By: Clevy
Just sayin


You know, there's a post on the first page with a brochure scan of Mobil officially recommending something different.

Just sayin'...

 

[Garak]

That's been explained on BITOG several times already. Incidentally, one thing being acceptable makes it neither optimal nor the only choice. I don't think anyone would doubt it would work, though.

 

[Peter_M]

Let's ask a hypothetical question then!

Let's say Doug is gifted a 1993 911 just like that owned by the OP.
Let's also say that the Australian government quarantines any further imports of Mobil 1, Delvac, Castrol, Fuchs or Shell oils so he can't rely on personal experience any more.
Let's also assume that Doug's not a hoarder of engine oil so the cupboard is bare, unlike many other BITOG'ers I gather.

He goes to his local auto parts store to buy engine oil.

What is his decision making process to select a suitable oil from what's left on the shelves for this particular car?

 

[UnclePeco]

Originally Posted By: rsamerica
Originally Posted By: UnclePeco
If you are near Scranton pa, I love working on those old air cooled engines and have some parts from prior cars I need to get rid of. Let me know if you are interested.


I'm about 30 miles north of Pittsburgh. Do you have anything interesting for 964 cars


Nope - mostly g50 and 915 911s with 3.2s.

 

[Shannow]

Originally Posted By: Peter_M
Let's ask a hypothetical question then!

Let's say Doug is gifted a 1993 911 just like that owned by the OP.
Let's also say that the Australian government quarantines any further imports of Mobil 1, Delvac, Castrol, Fuchs or Shell oils so he can't rely on personal experience any more.
Let's also assume that Doug's not a hoarder of engine oil so the cupboard is bare, unlike many other BITOG'ers I gather.

He goes to his local auto parts store to buy engine oil.

What is his decision making process to select a suitable oil from what's left on the shelves for this particular car?


If you were to give me the car under those circumstances, probably end up with Penrite 10tenths racing in it.

The 10W40 has an HTHS of 4.4

 

[Doug Hillary]

Hi,
Peter - My first criteria would be for a ACEA A3/B3 compliant lubricant at a viscosity of 5W-40 - failing that I would use a 15W-40 HDEO of CJ-4/SN

I always used Delvac 1 5W-40 in my last Boxster, and used Shell Helix Ultra 5W-40 initially in my last 928S4 before switching to Delvac. I used the Delvac product in my Series 60 Detroit OTR vehicles

I don't hoard lubricants but always keep one OC quantity on hand as I live in a quite remote part of Queensland's Tropics and supplies are "difficult" to obtain at times

When I first joined BITOG (and on certain Porsche Forums too) I was widely criticised for mentioning ACEA criteria and HTHS viscosity. They were virtually unheard of!! API ruled!!!!

Perhaps we've come a long way...................?