Here are the results of my annual end-of-season oil test (just before putting the car away for the winter I change the oil and send a sample to Blackstone for analysis). This year I specifically asked about any early signs of IMS 'issues' - see report comments.

How many miles do you have on that oil? Is that the 3,227 number?

Since Porsche recommends 15-20k between oil changes (depending on year) I'm a bit surprised the tech's assessment is that the oil (paraphrased) "can go at least 5k miles or more". If it was good for $15k, I think he would have given a higher number.

Yep, that's miles on the oil. I test yearly to see if it's possible to detect any issues in the event of a bearing failure. Of course that assumes bearings 'fail slowly', and would give enough time for the results to show up in the oil as a precursor to actual bearing failure, but I'm not sure that's how it works in real life. At the very least it's peace of mind that things seem 'normal' from a lubrication standpoint, but to your point does call in to question the wisdom of 15k oil changes.

- JohnL
Boston, 01S

Every manual i have ever read defines normal service, and sets the interval for normal service. Then they define "severe service" and suggest halving the interval. Severe service then includes hot, cold, hard driving, occasional driving, stop-and-go driving, towing, mountain driving and apparently driving while breathing.

So think more like "7500" miles which is close to 3200 + 5000.

Grant

Grant

gee-lenahan-at-gee-mail-dot-com

See 'oil and filter' column... 'official' recommendations up to 20,000 miles between oil changes!

[files2.porsche.com]〈=none&filetype=default&version=f49eb2bf-5dae-4800-b91a-64cee6b3763d

Quote
jlegelis
See 'oil and filter' column... 'official' recommendations up to 20,000 miles between oil changes!

[files2.porsche.com]〈=none&filetype=default&version=f49eb2bf-5dae-4800-b91a-64cee6b3763d

Interesting that ONLY 2005 - 2007 has a 2 year / 20,000 mi. oil change interval. Others are 2 year / 12,000 miles. Makes you wonder what's special about the 2005 - 2007 engines,

Then with the 9A1 engine, they've reduced it to 1 year / 10,000 miles

Essentially Porsche backed off, but what is done, and registered, is done.

I looked for the severe service wording. Only found part of it (below). If i have any time later ( unlikely) i'll pull it from another manual.


Grant

Grant

gee-lenahan-at-gee-mail-dot-com



Edited 1 time(s). Last edit at 12/14/2014 10:39AM by grant.
(view changes)

Quote
grant
Essentially Porsche backed off, but what is done, and registered, is done.

I looked for the severe service wording. Only found part of it (below). If i have any time later ( unlikely) i'll pull it from another manual.

k9e7ex.jpg

Grant

fall under that "severe usage" classification.

Unless one drives it long distances exclusively the car is going to experience "severe usage".

As I have mentioned before I change the oil in my engines every 5K miles. Sometimes this means I change the oil/filter then drive 5K miles in about a week's time because I change the oil just before I leave on a road trip and of course by the time I get home the car has covered 5K miles. (Once I had the oil change done on the road as I covered around 8K miles that time.) When I changed the oil after 5K miles the draining oil still had some amber color to it and was still a bit translucent. This is in contrast to the oil's appearance after having covered 5K miles even using the car day to day and even if this day to day usage involved a 5 sometimes 6 times a week 30 mile drive to work and back again mostly at highway speeds. The oil's appearance during these drains has the oil coming out black and with no translucence whatsoever. Now the oil wasn't as black as the oil that drained from my VW TDi. That oil was darker than the Ace of Spades no matter what even though once in a while it got the the pre-road trip oil/filter service followed by another after a week and 5K miles of driving. While the Boxster oil wasn't as dark as the Golf's oil, the Boxster oil was still quite dark, black, just not pitch black.

Also, some issues are harder to see - such as:

1 - dilution with water, fuel and acid
2 - depletion of the buffers that fight acids ( the "total base number")

Which is one reson that rather than agonize over the perfect oil, i often just change it a bit more ( and monitor it via UOA)

Grant

gee-lenahan-at-gee-mail-dot-com

Quote
grant
Also, some issues are harder to see - such as:

1 - dilution with water, fuel and acid
2 - depletion of the buffers that fight acids ( the "total base number")

Which is one reson that rather than agonize over the perfect oil, i often just change it a bit more ( and monitor it via UOA)

thing as ensuring one has selected the proper oil. A mediocre oil is not going to be helped by frequent changes. Sure, while this keeps the level of contamination down, even if the oil is free of any contaminates it must be up to the task of sufficiently lubricating the engine and this is required at the 1st mile after an oil change to the last mile before an oil change and at every mile in between.

(since you chose to go there)

Under other severe circumstances i also deviate from the norm and select a more appropriate grade.

That's not agonizing, that's simple science.
If hot, you need an oil that will maintain its intended properties under the circumstances it must operate in.

Now back to the intended topic - what i am referring to is folks who worry about this brand vs that brand vs 0w40 vs 5w40 vs whatever.

In the large, it doesn't matter. A fresh oil that is in grade, with additives and buffers, is better than a perfect oil which has lost viscosity at the top end, gained it at the bottom end, is 3% fuel, and a pH of 4. or whatever.

Grant

Grant

gee-lenahan-at-gee-mail-dot-com



Edited 1 time(s). Last edit at 12/16/2014 08:13AM by grant. (view changes)

Pretty much sums it up.

.. but sometimes it's because we're negotiating a tricky turn at the limit.; Apparently oil is under less stress when we are under more.

G

Grant

gee-lenahan-at-gee-mail-dot-com



Edited 1 time(s). Last edit at 12/16/2014 11:06AM by grant. (view changes)