Doug H

Hi, your UOA result is a very good one It is a shame that you cannot buy M1 5W-50 in the USA - it is a better lubricant for these engines if you wish to run a SAE50 lubricant That said, feel very pleased with the result - M1 15W-50 in either version is an excellent lubricant

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Hi Ed, lubricant colour is NOT a good indicator of its condition. A practiced person can do a "blotter test" to determine some aspects of contamination Many things can contribute to contamination A Used Oil Analysis (UOA) is the best way to determine the lubricant's condition. Blackstone appears to be a reputable LAB in NA

Hi, White987S - Of course the engine lubricant was changed as per Porsche's service schedule - at around two year intervals or at the 20k km OCI points whichever was reached first

Hi, this is the latest Used Oil Analysis results from my 2.7 Tiptronic 986 Engine data M9622 & Tiptronic @ 98677kms (61260miles) Operation over 15677kms (9730 miles) A number of long high speed trips (85%) and a small amount (15%) of Urban running Revs rarely above 6k Location Australian Tropics - high humidity (up to 98%) Lubricant Mobil's Delvac 1 5w-40 (CI-4/SL) Lubricant condition Nitration = 14 Abs/cm Viscosity @ 40C = 88cCt (new lubricant is 93cSt) TBN 6.4 (new lubricant is 11) PQ Index <1 Elemental analysis Iron = 12 Aluminium = <1 Chromium = 1 Copper = 10 Lead = 1 Potassium = 6 Silicon = 18 (up due to gasket sealant) Sodium = 5 Oil consumption = nil Summary The lubricant was suitable for continued use and was well within all degradation paramaters I changed the lubricant and the filter The previous lubricant in this engine and from new was M1 0w-40 I hope this is of interest

Hi, using the aircon C6? Code my cooling system is constantly around 93C when fully warmed up. Lowest constant has been around 92C and the hottest 105C I live in the Tropics and these temperatures are with an ambient spread of around 22-38C Oil temperarture is ideal when in a band of around 90-96C

Hi, Westcoaster - No error, lubricants are very expensive here. I believe M1 5w-50 is about $A80 for 5 litres Your choice of viscosity is a wise one Regards Doug

Hi, Westcoaster - IMO your best bet is to stay with M1 0w-40 Once out of warranty Mobil 1 Turbo Diesel Truck 5w-40 (Delvac 1 5w-40) is a very good lubricant in these engines. It is as suitable as M1 5w-50 in the occasional DE due to its superior High Temperature High Shear (HTHS) viscosity over M1 0w-40. I use this lubricant all year round in the Northern QLD Tropics where I live M1 0w-40 is around $A108 for 5 litres Delvac 1 5w-40 is around $A85 for 5 litres Group 4 refers to the PAO structure of the base fluid and Group 5 refers to the ester base or (content). Both these lubricants are Group 4 base with around +/-20% ester content Regards Doug

Hi, Weastcoaster - The best viscosity for you (and most of us) is 0w-40. If you track the car then the 5w-50 version of M1 could be considered depending on the prevailing ambient temperature The Group 4/5 structure of M1 0w-40 is its great strength and why it is being increasing used by other Manufacturers as a Factory fill M1 0w-40 is one of the best lubricants ever made and at any price Regards Doug

Hi, yes Mobil 1 5w-50 is the only SAE50 viscosity lubricant Approved by Porsche. It is an excellent lubricant with a long history. It ia available in most Countries except the USA Mixing most Mobil 1 products to achieve a "supplementary" viscosity can be done without the risk of loosing the benefits of the overall base fluid/additive package There are two exceptions to this however. M1 0w-40 and M1 Turbo Diesel Truck 5w-40 (non Approved) should not be mixed with other Mobil 1 lubricants if you wish to retain their unique and quite sophisticated formulation I use the "parent" of M1 TDT 5w-40 - it is a Commercial lubricant called Delvac 1 5w-40 Regards Doug

Hi, I have been monitoring the temperature of my car a 2.7ltr for some time now Typically after a complete warm up it normally runs in a band from around 94C to 105C. It does rise with limited air flow (in traffic) and falls again to around the mid/upper 90s once air flow is re-established I live in the Tropics Regards Doug

Hi, perhaps as here in Australia the "fail safe" source is the local area Mobil Distributor We are able to purchase it here in 5ltr containers at most Mobil S Stns and most discount Parts/Accessory stores ExxonMobil are very poor retail Marketers in my opinion! Regards Doug

Hi, Paul you are doing the right thing. You are also correct in not focusing on a few ppm here and there - especially if lubricant Brands are changed and etc. UOA is a complex task. To really understand the results and the implications requires much more than simply being a Lab. Technician - or a car Owner UOA results are very hard to replicate due to such things as Operator experience, Lab equipment type and etc. and of course the level of experience and knowledge of the Analyst With a new engine it is wise to commence a Trend database and look for the desirable downward trend in wear metal uptake along with no uptake spikes! Oil condition is important to monitor too as the experienced Analyst can perhaps detect coolant leaks and the like and the suitability of the lubricant to the engine I have found that getting both Total Base Number (TBN), (a falling value in used oil) and Total Acid Number (TAN) (a rising number in used oil) will assist in determining your best OCI if you do not want to stick with the engine maker’s suggested interval The PQ (Particle Quantifying) Index is a good addition to a UOA plan as it provides a real indication of the actual content of the larger and important ferrous metal wear debris UOA is at best a very good tool for providing a “snapshot” of the lubricant’s condition. In the hands of an experienced practitioner it can provide an insight into the way an engine’s components are wearing over time and is an excellent tool in the early detection of cooling system (and some other) potential problems Regards Doug Hillary

Hi, cnavarro - Charles you said this: "For what its worth, there are much better approved oils than M1 0w40." Can you substatiate this comment with some hard and unbiased facts please!! Your comment about draining the engine lubricant when at 50% of the original TBN is no doubt your opinion. Most engine manufacturers state that a TBN of 1 (D4739) or 2 (D2896 - ISO 3771) is the safe minimum - or 1/3 of the virgin TBN in diesel engines! This variance against your 50% would often represent the difference between the Porsche recommended OCI and far too early! This wastes a very valuable resource for NO benefit!! The unreliability of UOAs is well known in Tribology circles and I suggest that trending will assist in understanding the variances and variabilty Regards Doug Hillary

Hi Bill, yes the mysteries of Tribology are many! You will find Bob Is The Oil Guy (BITOG) an interesting and informative site All the best to you and yours for 2008 from Tropical North Queensland in Australia Kind Regards Doug