Changing your oil every 3000 miles is a waste of money and resources. Unless, of course, you track your car a lot.

http://www.edmunds.com/car-care/stop...-your-oil.html

 

My car burns a quart every 1000 miles. So in a way adding a quart every 1000 miles constantly refreshes my engine oil.

 

New porsche owner here, ...

What is the "normal" for the 997? When i got mine the dealer told me it was 10K.

I believe the manual reads 12K

that article says 20K

(On my case I do average driving, city/highways, 5 days a week, about 10K/year)

 

I do once a year or 7.5K, whichever comes first.

 

For the 997, Porsche indicated 12K miles until 2008 when they changed it to 12K miles. I suspect they learned something along the way. I would use 12k for all 997 base and S models.

 

10K miles a year assuming 5 days use per week and 50 weeks a year works out to 40 miles a day of usage.

On the surface 40 miles per day is a reasonably good number of miles but these cars are cold blooded, their engines anyhow. Lots of coolant and lots of oil to heat up.

The oil heat in particular is the key. If it does not get hot (above 212F) the normal accumulation of water and unburned gasoline doesn't boil out of the oil.

These fluids then build up and dilute the oil. The oil's abilty to protect the engine under high load/high temperature conditons is diminished.

Additionally the combustion byproducts combine with the water/unburned fuel to form acids which attack the internal components of the engine 24/7.

The only way to reduce the build up of water/unburned gasoline and the acids is to drain the oil and replace it with fresh.

While except for tracking or the most severe street usage (very very short trips) 3K mile oil/filter services are uncalled for in your car's case 10K miles between oil changes is in my layman's opinion stretching it a bit.

It is up to you of course but a twice a year oil/filter service given your usage would be my advise.

It was an oil analysis early on in the ownership of my Boxster -- with around 4K miles on the oil -- that found in spite of my usage of the car -- more than 250 miles a week -- that the water build up in the oil was rather high. So I decided to switch to a 5K mile oil/filter service instead of the (even then "crazy" 15K mile) service interval called out in the owners manual.

262K miles later the engine still runs just fine and is on its original IMSB.

Might add I follow the same 5K mile interval for my 996 Turbo and the engine has over 102K miles on it and runs as good as it ever has.

 

Once a year for me regardless of the miles.

 

Changing the oil is the cheapest way to maintain your vehicle ...yes I agree the 3,000 mile intervals of the past are gone. I do all of my vehicles around 5,000 miles because I drive hard and. It's not a big deal to change the oil especially if you buy all the components in bulk on sale.

 

Which is why oil change recommendations have a TIME SPAN as well as a mileage amount. The time span is there so that the very low mileage cars that don't properly heat their oil clean enough due to short trips, or infrequent driving, get the oil cycled. No?

 

Funny asking myself the same question. Had the car 6 months and only done 2k miles, I work from home or am away a lot before anyone chimes in :-)

Should I change?

 

Here's a related issue. According to the Maintenance Manual, transmission oil should be changed every 120K miles or 12 years! Well, I have always done mine around 35-45 K miles in every car I've owned, and did it on my 997 at 47K miles and 6 years.

 

I put around 6-7 per year. Weekend driver, I put about 100-200 miles per weekend. Change oil once a year, the engine did not fall off yet. :-)
However I have only 23k
Macster, thanks for the sensible/scientific answer.