RallyJon

Delvac1 is the fully synthetic diesel and heavy truck oil from Mobil. More of interest to us, it's a "real" synthetic made from Group IV/V basestocks that's a significant step up from the usual Mobil1 and at a price (I paid $7.12/qt) lower than Redline or Motul. It should last a very long time, even at high temps, without shearing out of grade.

Here's the VOA, if anyone is interested:

tj90

Thanks for sharing Jon - Ive seen it at Sams club and wondered why it would not work. Are you going to use it?

Freddy

Diesel engines are low rpm engines and are reved up to a maximum of 4.0000 rpm very seldom while ours go to 7.000 rpm almost every time we drive the car. Don’t they consider this when blending Delvac or Mobil 1 oils?

bgiere

Delvac 1 will work just fine. It is a fantastic oil. Many P car owners are using it.....

pcar964

Is it thick enough?

RallyJon

Well, it's thicker than the vaunted Motul 300V. Additive package isn't quite as robust, but still...

bgiere

HTHS is what you need to focus on. It is fine to use in 993's.

tj90

So who on the board is using it?

Also, why is the averages different than the analysis for the delvac?

From Mobil 1:

Question:
Mobil 1 vs. Mobil Delvac 1® for a Gasoline Engine
I have read on the Internet that Mobil Delvac 1 oils may provide better performance in high-performance passenger-car engines than regular Mobil 1, since they meet CF-4 specs. What about using Delvac in gasoline engines, especially high-performance engines?
-- "Tribological", Richmond, VA
Answer:
Mobil 1 formulas will deliver everything you need for your gasoline engine. In fact, during development, tests are run in both gasoline and diesel engines to demonstrate the superior performance of Mobil 1. Mobil Delvac 1, which is designed for heavy-duty diesels, meets most diesel engine oil specifications, and also meets API SL certification. And because Delvac 1 operates in a different environment – diesel engines run longer, generate soot and run hotter, it contains different types and amounts of additives than Mobil 1. Even so, Delvac 1 still meets API SL certification for gasoline engines, and because of its high performance, we would expect it to do a good job of protecting your gasoline engine. If you use your gasoline vehicle in "heavy-duty" service, Delvac 1 will provide many benefits compared to conventional oils. When compared to Mobil 1 performance, those benefits may not be as obvious, and in fact, Mobil 1 would be expected to outperform Delvac 1 in many gasoline applications.

tj90

Here is an old post from Dave at redline (co Robin). Im adding the viscosity of Delvac from the mobil DELVAC datasheet (http://www.imperialoil.ca/Canada-Eng..._Delvac_1.pdf:

fter that post, Dave from Redline oil shared some valuable testing data with me. Which I am sharing here with everyone. Of course the Mobil 1 oil is not avaliable in the 10W40 grade.

Robin,

I thought I would respond back to a note you posted a while bake on motor
oils, specifically 993 oils.
Some backround: these cars originally came with a 5W40 Mobil 1 oil not
available in this country, they now call for a 10W40 under all temperatures
in the US.

The viscosity in cSt of the (EU) 5W40 Mobil 1 is: 84 @40°C and 14.3 @100°C

The viscosity in cSt of the US Mobil1 15W50 is: 120 @40°C and 18 @100°C

>>>>>The viscosity in cSt of the US DELVAC 5W40 is: 95 @40°C and 15 @100°C

The viscosity in cSt of the Red Line 10W40 is: 102 @40°C and 15.3 @100°C

The viscosity in cSt of the US Mobil1 5W30 is: 53 @40°C and 9.9 @100°C

As you can see the 15W50 is substantially higher viscosity than is called
for at low temperatures.
You can see from this why I recommend the 10W40 for all around use, based
on the viscosity Porsche calls for.

The 0W30 is a lower viscosity than I would recommend in most 993 engines
except at very low temperatures.

The oil in the air cooled engines as you say plays a big part in cooling
the engine, a lower viscosity will transfer heat better than a higher
viscosity. I wouldn't say that an air cooled engine necessarily needs a
higher viscosity.

Where your temperatures range from 0 to 45° during the winter, the 10W40
would be suitable as well as in the summer.

The cylinders are somewhat oval when cold, then round out at temperature. I
wouldn't expect much seepage past the rings when sitting, the oil in the
sump typically sits below the cylinders. I think more of the smoke is from
oil seeping down past the intake guide.

Regards, Dave
Red Line Oil

Quadcammer

Is anybody running German Castrol Syntec 0W-30 in their 993s?

RallyJon

Couple of points:

1) The big difference between Delvac1 and Mobil1 is the basestock and the additive package. The basestocks are supposedly different/better/more of the expensive Group V to hold up to the extreme abuse of diesel engines. The additives are also designed for diesel engines.

2) A Group IV/V 5W40 shouldn't need viscosity improvers (which break down) to cover that range and therefore should be less susceptible than a 0W40 to shearing out of weight. If this were not a factor, we could all use 0W40/50/60 oil.

RallyJon

I asked Blackstone about the TBN, and it was 13.6, which is very high. Should be good for very long drain intervals.