gravedgr

Thanks for the info! I appreciate your opinions and they sound logical, but other posters (notably Doug Hillary who works in the oil industry) had produced conflicting information. I'm just trying to get a sense of who thinks what, and based on what background. It would seem that there are a number of people who feel as you do, and all of whom grew up working on engines (mostly as a hobby or semi-profession). I'm just wondering how much of that anecdotal experience (as opposed to experience gained working in oil or auto company labs) applies to Porsche's ultra-modern engine design and the synthetic oils they use.

No dig meant at your background, its just interesting to see. I don't think we will every have a final answer to this question.

Edgy01

Keep in mind that the 'break in' oil is quickly drained after the engines are run up and you get fresh Mobil 1 to drive off with whne you get the car. I personally plan to never change oil more than every 8-10,000 miles. Doug Hillary's explanations make the most sense to me.

Deven

This is what I have also heard, that the engine is 'bathed' with 100 litres of oil during the time it is taken to 'redline' at the factory. As a result, my suspicion is that most impurities/metal fillings etc are washed out. I too do not understand the logic of waiting for 20000 miles, especially since I am paying for the oil change, and since any future liability will fall on Porsche (if oil related engine issues occur). Maybe Porsche has tested 20000 mile oil and felt that it was still in good shape? Or maybe Mobil 1 has such data?

Murphyslaw explaination of the expansion/contraction makes a lot of sense, so the suggestion of taking long trips (with varing RPM) may not be the best way to 'break-in' the engine.

Mike Murphy

I just read up on Doug's posts, including some of his 10 oil testing reports. I think your point is a good one. Engines and oil from the 80's are different than what we have now. So, perhaps we can go longer than before.

My discussion was about break-in, so if Porsche engines are broken-in at the factory, and I did not know that they were, then we need not worry about that aspect. In that case, we should follow the "standard" oil change interval, whatever that happens to be.

Mike Murphy

I did not know that Porsche breaks-in the engines at the factory. I would be interested to learn more about this process. I guess I should not be suprised to learn that such an amazing company would go to such lengths to properly complete the build process.

Mike Murphy

Also, don't forget that Doug is quoted many times as sayding "I would NOT leave ANY oil in my vehicles longer than 12 months." This usually takes care of the 15,000-20,000 mile question, because few people drive that many miles on their P-cars.

gravedgr

Its so very refreshing to have a conversation about break-in and/or oil here and have all sides rational and open-minded about new information. 1999Porsche911 must be on vacation.

Deven

And I think that the Porsche manual suggests 20000 miles or annually for oil changes as well (I will have to re-read).

lazlo9

This sounds like the most practical advice. thanks!

cosmos

My other cars, BMW's come with free maintance.

I do lease the cars (except P cars) and I want the person after me to get a good strong car. I do however drive them sort of like I stole them.

That being said....I would do a oil and filter change at 1000 miles and then another at 5000, and then I dont touch it. BMW pays for all the other oil changes. The light comes on at 15k mile mark. It is supposed to be measured with the type of driving and other factors, but its almost at 15k miles on the dot.

BUT...on the GT3 I did an oil change at 1000, 1500 and then every 2500.

I also changed all fluids at the 1000 mile mark, tranny, diff and then did a brake fluid change, but that was to SRF.