MelissaM

I use Shell Rotella 20/50 in my '90 C2.

Here is are the recommended oil grades from the 1990 Owner's Manual:

Ambient Temperature: mostly greater than 50F/10C
SAE Viscosity Range (dino): 15W-40, 20W-50, 40

Ambient Temperature: mostly lower than 50F/10C
SAE Viscosity Range (dino): 15W-40, 10W-40, 10W-30

Ambient Temperature: mostly lower than 14F/-10C
SAE Viscosity Range (dino): 10W-30, 5W-30

For synthetic oil, they recommend as follows:

Higher temps: 10W-40, 15W-40, 15W-50
Lower temps: 10W-40, 10W-30, 5W-30

Hope this helps!

-- Melissa

Young_Turk

Thanks for the topic Monte.

Has anyone out there changed from dino to synth with high miles, and not suffered more leaks.

Is it better to stay with the dino with 90,000+, but change more frequently?

John Turk

ked

John, I acquired my '87 Coupe at 74K miles, good owner & service history, seemed to have had a diet of Castrol 20-50. About 1000 mi. / qt. consumption, no leaks. I switched to Mobil 1 15-50, same oil consumption rate, no leaks, except when I leave it unused for 2 weeks, then I see a little bit dripping from the center seam of the engine. Since I never left it unused that long before I switched, I can't say the minor drips are due to the synth oil. It doesn't show any loss onto the garage floor when I drive it weekly or better. Overall, I am very satisfied w/ the Mobil 1 & I'll stay with it. Even put their gear oil in my G50 trans with positive results (smooth, easy shifting) as well.

Arjan B.

Hello Adrian,

Tell me why 0W40 Mobil 1 is not good for older engines?
0W40 from Mobil and Bp is very good, anworks fine also in older engines is my experience.
I'm a servicemanager in a Gm {opel} dealership, and we use for all the cars, youg and old 0W40 Bp Visco 7000. Special now that the cars coming very much later for service as 2 years ago.
The 0 is the visc./condition in cold shape, the 40 in hot shape of the engine. So 15W40 is the oil in cold condition less thinner then 5W and 0W.
The only thing whe had is that some engine's use a little more oil during milage as usual, but the oil is faster then ever where it should be, less wear, less carbon dubris.
I now this, because when I worked at a Jaguar/Ferrari dealership 3 years ago, we had the XJ types, they used more oil with Mobil 1, but no damage from this oil.
The protectiong factor is better, because the engine wears most in cold condition and cold starts as you know.

Porsche in the Netherlands use Mobil 1 and I hear never any complains.

Pleas tell me and everybody else who is interested, what your reason is to use no 0W40 oil.


Greetings,
Arjan Brinkcate
964 C2 1992

George Stevens

Arjan

You do have a good point, I used to own a 1977 Carrera 3.0 which at first I ran on Mobil 1

Whilst it clearly didn't harm the engine, oil consumption was higher than using a semi synthetic. Really Mobil 1 was probably too good for a car of this age and mileage (110,000).

My current 70,000 mile RS runs on Mobil 1 and oil consumption is very low.

The official Porsche centres and many independant specialists here in the UK use both Synthetic and Semi-Synthetic depending on age. mileage and customer budget.

In a high mileage 964 I would save money and oil consumption and use a high quality semi-synthetic

Here in the UK Castrol Magnetec is often recommended as a good quality semi-synthetic