How many miles before oil change

[MLCN911]

I bought my 2010 911 last September with 900 miles on it. I had the oil changed at 1200 miles and again at 14000 miles.  I now have 21000, I drive it a lot, all highway driving. I work in MD and live in Reading. I have decided to stop driving it to work(no the thrill isnt gone). I just decided to drive the truck more. Porsche says 15000 with mobil 1. Im thinking of doing it every 7500, but a friend told me its a waste. Any thoughts?

[michael lang]

My opinion is you can never do too many oil changes. I think I average about 2000-2500 miles between changes. I don't put in any MOAs and I give the used oil to one of my techs who pours it into his heater for his garage. Since there is no additives, and it is relatively clean it burns extremely nice and helps him keep his garage warm in the winter. So there really isn't any waste.

[the_vetman]

Well, the most "scientific" way to figure this out may be doing oil analysis after each oil change. Ideal change interval could depend on your car, driving style, whether you track, condition of the engine, etc., etc.

Porsche may recommend 10,000-20,000 miles between each change but many recommend doing it every 5,000 miles. Oil is cheap; your engine is not. However, some call this a waste based on oil analyses. YMMV.

If you track your car, changing more frequently than 5,000 miles is often recommended.