Try Loren's site (renntech.org). He has a wealth of TECH information. Very good site. I have been a member for some time and visit it at least once a day.

 

someone mentioned before that they change their oil based on track hours. every 10 hours or so of DE driving they change the oil. sounds like a pretty good plan for me, since i track my car fairly often

 

I'm with Pierre and others, if the factory says 15K miles, then change it then. I did mine every 12K miles or so, but only because the dealer was doing other work and I got a good deal on the change at those points. It wasn't much more than doing it myself (once it was free!), so I figured I'd just let them do it.

The detergents in Mobil 1 will last 25K miles, but the filter in the car starts to wear out around 15K. Plus nobody is going to recommend a 25K oil change interval for a car!

 

every 3000 miles

 

My dealer told me that Porsche stretched its change intervals in part because it counts against them as emissions somehow.
I'm changing mine myself at 5k intervals, and having my dealer do the 15k intervals, just to get a stamp in the book. I trust myself *way* more than I trust the goon at the dealer, though.

 

I'm not an engineer, so when the Porsche engineers say "15K", I say "yessir!"

 

Stiles is right! NOTE: MY PERIOD KEY IS BROKEN

At least in the US, cars are measured on total emissions including used oil, That is why you see the very long oil change intervals, On my race car I change the oil after every race weekend, On a street car I would never go beyond 5000, I don't think you will find an independent Porsche mechanic that would disagree,
Jim

 

I say change it every year - but that's just my opinion... then again, I don't change my underwear everyday either.... eww. Ok, I'm kidding.

 

I change mine every 10k miles. 0w-40 Mobil-1.

 

i think this would be a good topic for a poll.

i do find it interesting that pierre follows the factory rec and has done well.

i change oil every 15k mi both for my c4s and 996tt--the oil seems so clean when i change it that i am confident i'm doing the right thing

 

At least we are all at or below the suggested interval. It never hurts to change more often but it can be detremental if you change too late!