etom

I couldn't find out with a search what the numbers might be like for 964 owners when it came to which oil was preferre--if the choice, that is, was synthetic vs. convential.

Maybe someone could set up a poll? I'd be curious . . .

Ritter v4.0

Results Prediction

Mobil 1: 99.7%
Other: 0.3%

Rennen

I just switched to Mobil 1 V-Twin Synthetic 20W50.

TR6

What's this I keep hearing about people using Rotella? I run it in my diesel, but in a 911??? What's the advantage?

parsecnc4

Mobil Delvac and Royal Purple in my various older cars, but will probably will try Swepco on my next change on the 964.

There was a more recent discussion on the benefits of Rotella or other oils for diesel as well as motorcycles.

https://rennlist.com/forums/showthre...ight=scare+the

springer3

I am not sure switching brands and grades is a good idea. Seals are conditioned (damaged) by the oil. Changing to a new formula risks further "conditioning" of the seals. I use the same oil brand and viscosity as the PO, who was the original owner. So far no leaks. Only 61,000 miles, but 16 years same as everyone else..

boze_man

there was something on pelican bout this...

seems like reduction in zinc or phosphorus or something etc in the new 'SM' formulation oils is not good for an older 911 esp SC's... not sure if it applies to 964 and newer??? ....rotella has higher amts of these additives i believe...the SM formulation of MOBIL1 has too low of an amt...interesting read to say the least...the internet is amazing

click the link below to learn more...
http://www.lnengineering.com/oil.html

here is a pelican thread on it...
http://forums.pelicanparts.com/showthread.php?t=332678

jimq

I use Castrol Syntex in the 964 and Mobil 1 in the Turbo. Guess I am the .3 % guy

parsecnc4

I agree that sticking with the same brand and weight of oils would be best, but the "grades" of oil on the same favorite brand and weight have been changing in the last year or so. The recent developments seem to be catered to lower emissions and for mechanicals designed for less frequent drain intervals.

I am for one brand one oil for each of my cars if only the formulation does not change for the worse for our older engines. Given that I am not an oil expert, I can only read up and employ the best practice applicable to my cars. If it is good enough for the racers and engine builders, it is good enough for me.

pat056

One thing I was told. The synthetic is "thinner" hence may make your weeping engine a leaking engine.
That being said, I run Mobile and let it weep or leak. As hard as I run my car and as often as I check/change the oil, I don't worry about it. I want the best protection.
I do agree with the philosopy of pick a system/brand and stick to it.

FRporscheman

My dad bought a 964 which was advertised as "leaking badly", and it would leave an oil slick on the ground. When we got it, I topped off the low oil with conventional oil, and the leak stopped.

From now on, in that car, I will use conventional. Until we rebuild it, anyway. I'm just trying to figure out what brand and weight would be best. I've had good experiences with Valvoline in my 944s and 968s, but I was thinking maybe Mobil 5000 or something.

tbennett017

We make .6%.... I use Castrol Syntex too.. but mainly since I couldn't find the Mobil 1 when I was looking.

I know Wal Mart sells large containers of oils.. but can one get gallon size or larger volumes of Mobil 1 anywhere?

ilko

Wal-Mart sells 5 quart jugs of Mobil 1: https://rennlist.com/forums/993-forum/385370-5-quart-oil-jugs-walmart-go-now.html

jgrosjean

I have been using 15W-40 diesel oil in all my Porsches for 30 years. The C2 currently uses it. Never had a problem. If you have leaks, it will slow them down a lot.

Larry Herman

Amsoil fully synthetic...20w-50 racing oil in the RSA, 15-w40 diesel/marine in the truck and 5w-30 in everything else.