Hi,
Terry - yes we have rarely disagreed over the years and I welcome your comments
Porsche ownership is complex - and it has an unusual group of demographics. Many owners do less that 5k per annum, are above 55 years of age and without much mechanical "nouse" - most do not need it! Most Porsche owners are very conservative drivers
As you are probably aware, some Porsche owners use their cars for "Club Days" or track events Most of this is done as an adjunct to day to day commuting and on a VERY limited budget
Serious owners race them seriously, but that is only a very very small portion of owners. Many Porsche race engines are rebuilt after 200hrs or so, but then racing is really a separate issue
And yes, as I indicated too, viscosity is but one part of the Manufacturer's Approval proptocol
I had also said this a little earlier than your extract;
" The Approval and Listing of oils by the factory is important due to the characteristics of these engines"
The Porsche Approval protocols and recommendations are based on serious engine data collected since the early 1970s
This real world experience has confirmed the limited viscosity choice of 0w-40 (below -25C) or 5w-40 all year round, and only one other heavier oil - M1 5w-50 is Listed
It is now so limited that only 0w-40 lubricants are endorsed for the Cayenne V8s - and with very good reasons too!
Porsche thought so much about this issue, considering International Brand loyalty, length of ownership the number of Porsches per family etc that they made their List applicable to all engines built for MY1973
There are about 130 lubricants Listed
As well as ACEA A3/B3, one Porsche specific test protocol for instance is foaming control - foaming was a real issue in some Porsche engines
There are others too including oil durability which includes extended viscosity testing, volatility and etc
Much of this has to do with valve actuation components and engine breathing arrangements
Some Porsche engines have been known to suffer technical "issues" so they are not perfect either - some are far from it too
Many 911 engines are rebuilt under 200k, another Porsche engine family has engine nearing 1m kms without being touched!
An enormous complication is the very complex nature of the technologies and mettalurgy used over the life of the "911" for instance. Air/oil cooling, air/coolant cooling, coolant cooling. Aluminium, Magnesium, Nikasil, roller and flat cams, variable cams with three lobes per valve, wet and dry sumps, with or without oil coolers of various types (trombone, air to oil coolant to oil), turbos (one or two) and etc. And a plethora of options and add-ons to go with it
all
What annoys me most of all for "average non technical" owners is the amount of misinformation that abounds. For instance we have some engines here running 27w-60 oil "because my Porsche mechanic said to.....!"
In America some dealers were changeing M1 0w-40 at 3k "...because it needs it..."!
The Porsche engine lubricant Approval system and the eventual Listing of those oils that are submitted and pass the protocols is the best insurance an average owner can have. Along with his handbook listed OCIs etc of course!
The Porsche component trash can is littered with engines that have failed when using non Approved lubricants with an HTHS vis of around 2.7cSt (min is 3.6cSt) when being tracked. Or engines that have been trashed having used so much oil going down an Autobahn at 200kmh for hours
Every time the oil is non Approved - not viscous enough, too volatile or with unstable viscosity characteristics at high engine load/oil temperature. And there can be serious durability problems when using mineral 20w>-50> oils
The easiest way I have found is to alert Porsche owners that the Listed oils DO work - the Brand is largly irrelevant
Serious racing is another issue and the Shell Ferrari/Mobil Porsche approach seems to work well there too
The GT3 series here has many cars running non Approved FUCHS 0w-20 GT1 lubricants - with no failures to date that I am aware of
As I stated earlier the most popular oil used in older Porsche engines is M1 (5w)15w-50 and from one side of the world to the other. And never more so than in the US - well you can't buy M1 5w-50 there, sorry about that
So no disagreements Terry - but this thread was really about a reasonably good UOA on an oil that I would not use. He has now changed to one I would use if I owned his car, that was a great choice IMHO
I'll stick to Delvac 1 5w-40 in mine - it is NOT on the Approval List but it is the correct viscosity and the nine UOAs to date show it works very well indeed
Respectfully
Doug