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dewolf dewolf is offline
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Join Date: Jan 2007
Location: Australia
Posts: 6,877
Mobil Delvac1. I have read that Porsche ok the use of diesel oils ( not sure about new cars) , correct me if I'm wrong. Email from chemical engineer.

Hi Scott,
firstly BB is a topic I prefer not to comment on except to say that how some
people survive in business truely amazes me

Firstly is Delvac 1 5w-40 better than Mobil 1 (say 5w-50) well, yes it is.
(In some applications M1 0w-40 may be a better choice - I use it in my new
CLK Benz)
The biggest advantage Delvac 1 has is that it has around 25% sophisticated
ester content - this is beneficial at high/low temps, for engine
cleanliness, for viscosity retention and for protecting oil seal integrity.
It also has a very high TBN which protects low use engines from camshaft
corrosion and etc due to rising acidity from combustion processes. Its ester
content is especially good at minimising journal bearing, valve drive
components (lobes/chains/gears/sprockets) and thrust washer wear

Delvac 1 5w-40 will do an excellent job in your car. It conforms with the
viscosity requirements for your car and exceeds the specifications required
by a substantial margin. As well it conforms with Porsche's Approved Oils
List (911 D 1701 1) of 29/12/2000 and then later superceded in 2004 with
only synthetic oils being Approved

The 911 first came out with a "mixed fleet" diesel oil as the factory fill.
This continued Porsche's use of diesel oils from the 356 onwards. This was
later changed to include multigrade oils but still with dual petrol/diesel
ratings. It is still the same today!

I have used Delvac 1 5w-40 since 1997 in a wide variety of engine types. In
a 911 such an oil has some desirable attributes. It is very robust at high
temperatures - great with turbochargers- and it is especially forumlated to
resist foaming and losing/gaining viscosity over long periods

You may notice a slight drop in oil pressure at idle due to the oils (all
synthetics but especially Mobil 1) superior flow characteristics. Flow of
course remains the same but better flow charcteristics of the synthetic
lubricant tends to reduce pressure. (Pressure is simply the resistance to
Flow of course).
It should help the engine run cooler than a mineral oil does - if you are
using one now

What oil do you currently use?

NOTE - I do not work for any Oil Company - I did for some years -
Caltex-Chevron in Copenhagen, Denmark in the 1960s. I first worked on
Porsches then!
I am retired!!

In Heaven… the mechanics are German, the chefs are French, the police are British, the lovers are Italian and everything is organized by the Swiss.
In Hell…the mechanics are French, the police are German, the chefs are British, the lovers are Swiss and everything is organized by the Italians.
Old 01-17-2007, 03:28 AM
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