When To Change Oil

[Brucelee]

"I personally never bought into the 3000 mile change intervals. Those have been engrained on the population by the Jiffy Lubes of the world for the sole purpose of boosting their bottom line. No major engine manufacturer ever specified those intervals for normal driving conditions."

Actually, the 3K change with DINO oil was not a bad thing. DINO oil performance drops off VERY QUICKLY as it wears, SYN does not. The hard analysis that I have seen on DINO would support the 3-5K changes with DINO, not SYN of course.

"I think if you were to get access to the engineering data within Porsche you would find that even with the 15,000 oil change interval the oil's ability to protect the engine is well within spec. I wouldn't doubt if their data shows acceptable wear well past 20K intervals. Rest assured that they are not going to specify longer intervals at the risk of higher warranty claims."

I have never seen data (even from AMSOIL) that would support 15 to 20 K changes UNLESS the oil filter was changed at about 12,500 or so.

M1 is pretty much shot at 11-12K without an oil filter change.

I would be ASTONISHED if Porsche had hard data that showed that m1 could run 20 K without an oil filter change and be up to snuff.

In fact, M1 extended perf oil is only claimed to be good to 15K. AMSOIL will guarantee 25K IF you change the filter about half way.


"Oh, and one more thing regarding the "5 minute" dyno runs. That is the portion of the run after the initial warm up phase that puts the engine through it's paces. On a modern computer controlled engine dyno you can properly break in an engine in a matter of minutes. Again, more is not always better."

I would love to see some back up for this statement. Break in has to do with bearings, metal to metal, and ring seating. How does the computer speed up that process?

I do think the "bashing" you refer to is valid. If Porsche specifies 20K on the oil, it would have more credibility if it had many less failures to explain.

PS- I love Porsche but am not blind to their blindness on certain issues.