Hi,
hutchingsp - This thread has developed very well indeed. I hope I can remain objective!
Firstly, Porsche have ALWAYS had long OCIs, ever since they started building cars and engines for sale - from around 1955! Over 50 years!!!
Secondly I don’t believe that Porsche were foolish in establishing the two years and 32kkms (20k miles) maximum OCI service policy when using their Approved and Listed lubricants.
Some other Euro engine makers have done so too
It serves to remind us that we are using a very valuable resource and that their research has shown that the Approved and Listed lubricants will do the job very well indeed - any of the 100 or so on the their List! In our near future we will see two or more years or “lifetime” fill become commonplace across a raft of engine manufacturers!
It is interesting to note that Porsche carried out a systematic and well controlled UOA programme in NA commencing with MY02 and continued it for some years. They will have data that we can but dream about! They do NOT set services intervals at levels that would impact on Warranty and/or durability
I also carried out testing commencing some years ago to prove/disprove Porsche’s policy after a well known Porsche service provider in California (and another here in Sydney) promoted the “fallacy” of it and that his subjective and wrong policy of 3k miles OCI regardless was correct! My testing to establish the point (see RENNLIST 928 Forum - search “Oil Condition Report”) over nearly four years showed that the 20kkms (12k miles) or two year OCI is actually very conservative! This programme is continuing amongst some 928 owners here in OZ with records going into my database
For those persons who don’t agree with the (any) engine’s manufacturer, they can simply use UOAs to establish an OCI that they feel comfortable with - it’s as simple as that really
For many, the real problem with UOAs is in the interpretation - especially the level and source of wear metals. Many chase “spooks” in this area! Some people still believe that single pass UOAs with different lubricants will tell a true wear history of the engine and how good/bad a lubricant is!
As we know (and have done for 60 years or so) , UOAs are excellent tool for determining the OCI in most machinery - and it is always wise to remember that wear metals are accumulative! As an example I have run many of my very expensive ($45000) engines with iron at up to 150ppm when at the lubricant’s condemnation point - and their overall durability has been really exceptional. Some engines are now at 2m kms (1.24m miles) without a rebuild!
Both Porsche and Benz in this country (and in Germany) are very happy with the performance of M1 0w-40 which is mandatory in OZ - and Benz have much local data to back it up! Their average OCI is around 18k kms!
My CLK Benz (on M1 0w-40) has a “reactive” service indicator and it runs at around 15k-17k OCIs
As for other lubricants, the Porsche Approved List contains around 100 Brands/versions and around 80% are of 5w-40 viscosity - the balance are 0w-40 viscosity. There is only one SAE50 lubricant, Mobil 1 5w-50! I believe that they will all perform about the same and I am very sure that Porsche know this.
The performance margins from one to another in engine life/durability and etc. will be VERY minor indeed!
Technicians from Stuttgart (some ex the 1960-1970s racing programme) that I have spent time with are adamant that M1 0w-40 is “the” lubricant for all road going Porsches - and they use it for racing too in late series engines!
I have yet to hear of an engine using M1 0w-40 that has suffered any sort of measurable “excessive” wear or lubricant related issue - from Porsche, Benz or Mobil - or from any owners! I have seen a number of high “mileage” Porsche and Benz engines that have used this lubricant from new and they have all been internally clean, consumption low and with no discernible wear being evident in the valve train region
M1 0w-40 sells here within a price range of from $65 to $95 for a 5 litre pack. Porsche charges about $25 for a filter
My use of a non Approved 5w-40 synthetic lubricant in my Porsche is based on past history - and with the approval of Porsche here in OZ. They know my history quite well! I know the history of their M96 engine too. And, I am fully aware about the structure and performance of the lubricant after many years of use and I purchase it in "bulk"
I live in the Tropics too where an average cold start in summer is 27C and in winter about 10C - maximum ambient is over 40C and humidity can be 90%>
With MY2007 cars Porsche will pull the two years point back to one year - this is due to the conversion of all engine families to Direct Injection (DI) from that point! A 0w-40 viscosity lubricant will still be the only one permitted in the twin turbo V8 engine family!
I am retired and I do NOT have an affiliation with any Oil Company. I selectively use Mobil, Castrol and Shell lubricants in my vehicles
Now, being totally objective, it is wise to remember that there really is no magic lubricant!
Regards
Doug