Recommended oil for a Porsche 911 S (year 1.976)

[juankimalo]

Hi guys:

In Soloporsche.com forum there are some fellows who are discussing about what oil is the correct choice for an aircooled engine.

There are:

- Porsche 911 S (year 1976)
- Porsche 964 (year 1.990)
- Porsche 911 Carrera 3.2 (year 1.986)

We know that early Porsches (pre-74 models) use mineral oils.


They are discussing between Motul 300V 15W50, Valvoline Racing 20W50 (mineral), Gulf 15W40...

Could you advice us about these questions please?

There are lots of Porsche approved oils in the official list, but they are proper for modern engines.

Thanks in advance

 

[Doug Hillary]

Hi,
juankimalo - Provided in the absence of any other replies to you

Porsche's A40 Approved List goes back to 1984 - and covers all vehicles back to that point

Porsche used HD 20W-20, 30 and 40 as a Factory Fill in their 356 and 911 engines well into the 1970s, these lubricants were from Shell's Rotella/Rimula range

Old "Technische Information" D1701 Lists covered all Porsche engines going back to 1973

The viscosities on the 1999 D1701 List of about 110 lubricants were;

0W30^
5W-30^
0W-40*
5W-40*
10W-40*
10W-50#
10W-60#

^SAE30 was later removed and do not appear on Lists after 1999
*SAE40 was the most common viscosity
#SAE50 and SAE60 were later removed and do not appear on Lists after 1999

No 20W-50 lubricants were Approved!

A common suggestion for "average use" in engines up to 1984 is a 10W-40 or a 15W-40 HD viscosity lubricant. A 15W-40 HDEO is a good choice as these typically have great antifoaming abilites along with good viscosity retention. These things must be considered due to the 911's dry sump system and multi oil pumps

A 15W-40 is used in older cars (off the A40) List by Dealers here in Australia now as I understand it. The Zuffenhausen Musuem still uses 15W-40 and 20W-50 (pre warmed to 80C) in their Collection cars IIRC!

So I suggest a 15W-40 HDEO in all of the cars you mention if they are not raced or used in severe Winter conditions!

Some European Owners use M1 5W-50 in older cars that have been rebuilt and/or "resealed" and some US Owners use M1 15W-50

As can be seen from above for "normal" street use a SAE40 lubricant is what is really needed not an SAE50 lubricant

 

[juankimalo]

Hello Doug:


Thanks for the information/advices

I showed this post translated into spanish to my fellows.


Regards from Spain