Oil Change Frequency for Boxster?

[hytem]

My last Mobil 1 change was done about 4500 miles and 10 months ago, when I bought my '03 Boxster. I drive about 6K miles per year or so, mixed driving.
Car always garaged and driven moderately--no tracking.

Should an oil change be done at 12 months, or can I wait another year to 12K miles?

The car hasn't used any oil so far.

[Rick V]

My 97 is a daily driver, it gets 18-20 k a year, Mobile 1, and i change it every 4k no excuses

[mhknapp]

Not quit as good as you guys, car gets around 5k per year, change the oil Mobil 1 every 6 months.

[Doug&Julie]

The factory says every 15k miles, or once a year. (My brother's Cayman S says every 20k miles!) If you don't do the miles, I'd say you're fine with just once a year. I certainly wouldn't wait any longer.

[superglide]

I average 5-6k mi/yr on my '00'S', & change oil every christmas time. BUT; I change the filter @ 3k mi intervals. Seems to have worked fine, so far.....

[JMatta]

The original post is dated, but if you read Jake Raby's (flat6innovations) comments on oil changes, I certainly wouldn't wait any longer than 5-6k miles. I change mine yearly, but that equates to around 2500 miles.

[superglide]

Yeah, the book (Bentley's & Owner's manual) says 15k mi, but 5k is my max..... With synthetic lube, I feel that frequent filter changes are more critical, though there are engineering papers out there which say that an engine in proper tune and working order could (theoretically) go 25k between changes with synthetic. But I don't put much on theory.... Amsoil, who claims to have originally formulated syn oil for jet engine application, has some interesting technical info (lots of it) on their website.

[cnavarro]

5k or 6 months is what we recommend. Used oil analysis agrees with this interval.

Cars that see track time, I've heard of changes every ten hours or roughly every other event on average.

This is spot on with what we run on aircooled 911s.

[superglide]

Charles, do aircooled engines have a different interval/window, than the liquid cooled (996/986)? Is there a mandatory time frame, as opposed to milage, for synthetic oil change? I only average 5k/yr, but definitely change every Christmas (convenient reminder). This stuff doesn't rot, like the old Castrol'R' does it?

[cnavarro]

Used oil analysis has pretty much shown that the intervals are about the same. The matter of time vs. mileage is a difficult one to balance. If not driven alot, you have fuel (or combustion byproducts) in the oil that further causes corrosive wear and reduces the TBN. Also, driving habits also affect drain intervals - short drives require more frequent changes. Longer drives where the oil gets nice and hot is actually better for the oil and lengthens its service life. The blanket recommendation of every 5k or 6 months is a safe one, that's why I make it. Synthetic versus non-synthetic does not change this. And no, the oil doesn't rot. The additive package can settle over time and moisture will reduce the TBN, but that takes a while while oil is virgin and in storage (in it's packaging).

[Porsche_Daddy]

Originally Posted by Doug&Julie

The factory says every 15k miles, or once a year. (My brother's Cayman S says every 20k miles!) If you don't do the miles, I'd say you're fine with just once a year. I certainly wouldn't wait any longer.

Things may have changed since 2003, but my owners manual says change it every 15k miles or every 2 years. Oh, and it says change the filter every other oil change. Not what I follow, but I think people a lot of people change their oil way to often.

[cnavarro]

The 5k/6 month recommendation is based of off used oil analysis, so it is sound. You should change the filter every change (it's a very small filter). The factory drain intervals are rediculously long. You could stretch it to 10k, but the oil is shot well before that (also verified with used oil analysis).