Okay,



I'm finally compelled to take an informal survey.


Please state your year, motor, approx. annual mileage and observed oil usage.


I've got nearly 4,000 miles on my 3.8l motor now (Since May 1!), and have added 3.5 quarts already.



This seems high to me, and I'd like to collect some independent information from my esteemed friends here on the board.

Cheers,
Gundo

 

Polls like this are often for the sole purpose to help the pollster to sleep better at night seeing that there are others who experience the same problem. The fact is, no matter how many Porsche's you find that burn a measurable amount of oil (non track) you have a problem.

The engine was not designed to burn oil and burning oil is ALWAYS bad for the engine as well as it robs the engine of power. In many cases, burning oil on a NA engine is due to using the incorrect oil and driving the vehicle like it is a show car, allowing your cylinders to coke up and rings not to seal. This creates tremendous crankcase pressure forcing oil into the intake, reducing the effective octane level of the fuel. Long term negative effects is carbon buildup in areas out of the airflow path, hotter engine temps, etc.

Rather than looking to see that your engine is like every other Porsche, it would be time better spent fixing the problem. I have found very few flat six NA engines that I couldn't stop all measurable oil loss without breaking into the engine.

Remember, synthetic oil is not amume from sludge and carbon buildup as the marketer's would like you to believe. Too thin an oil is more prone to this as it is effected more by ring leakage and crankcase pressure.

 

Appreciate your comments.

As a long-term Porsche owner, I find these polls help tremendously by increasing our collective knowledge. I've polled the Boxster community, and the consistent response is that oil usage is very low for both 2.7l and 3.2l motors driven on both street and track.

As for using the incorrect oil, my guess is you'll be hard pressed to find many late model 911 owners not using Mobil 1 0W40. And with respect to driving like a show car, you've got a point, as there are definitely board members that own garage queens and haven't seen the high side of 5k rpms.

I'll add, that the service manager and Porsche's manual states that the 997 motor will burn 1 quart per 900 to 1,100 miles. 1 quart per 650 to 850 on the 997 Turbo.

 

So much for the theory of our engines not being designed to use oil.

 

My 2007 C2S Cab. has 1200 miles on it and the oil indicator is down 1 block from full.
This is my sixth 911 going back to 1981 and the only one I have not followed the owner's manual break in period re. rpm's during the first 2000 miles. I have red lined this one since mile 1.
I have not noticed any difference in oil consumption with this car versus previous models. My 2005 C2S was broken in according to the book and I added 1 quart of Mobil 1 after 1600 miles.

 

Just because a manufacturer states that an engine will burn oil, does not mean that it should. They realize that MOST drive a Porsche for the "bling" factor and therefere do not drive the car as it should be. It is called "covering your ***". I suspect that Porsche will soon incorporate in the manual that it is not wise to engine break your car while in second gear. This will eliminate all liability for the 2nd gear pop out issue in the TT's.

I am amazed, how over the years, Porsche (more so that any other manufacturer) simply responds to customer complaints by incorporating a problem in the next manual or TSB as being "normal". But what is even more amazing is how many owners accept the explaination.

Maybe more of you should not accept it as normal and start doing something to correct the problem. Even better; lets hear from someone who will try to convince us why burning oil is normal, why it is NOT bad for the engine and why it DOES not affect performance. Should make for an interesting discussion.

As far as polls; of all the Porsche's I have owned, knew through people who owned them or otherwsie been involved in them, maybe 5% had an oil burning problem. But, then again, not one of them ran Mobil water in the crankcase and drove the car properly.

IMO, I think it is misguided to think you can determine what is normal by relying on a forum that represents a small sampling of Porsche owners and is often frequented by owners who have problems in the first place.

As for me, I would not accept that my engine should burn 38 guarts ( 9.5 gallons) of oil in between 15,000 mile oil changes.

 

8900+ miles and I've done 4 track days and an auto cross and 1 oil change at 7000 miles. I've burned about .5 quart of oil before the oil change and none since. I keep hearing about all this oil burning and I monitor my oil at every start up and I just do not burn oil.

I got the car and it had 52miles on it brand new. I sort of followed the break in but not exactly as I did strong accelleration up to around 5k and held the gear and let it off throttle down to 2k and I varied the rpms a lot I did quick red line run at around 1200k and started tracking it at 2000 miles.

 

06 997 S, 16 months old, 15K miles, 1Qt each 4000 miles, Changed oil at 7K.

 

1999 Porsche911 posts the same response to all inquiries regarding oil consumption. He will next tell you to use unauthorized visc. of oil because he believes it is the right thing to do. Judging by message board responses to this sort of question it appears most of these engines will consume some oil if driven as intended. If driven very lightly you can get condensation in the oil which belies the process. If driven at high speed on the Autobahn you may approach Porsches high consumption figures.(or so sez Excellence) My guesstimate having spent too much time obsessing over this topic is that most of these cars, if driven as intended seem to comsume a qt every 2-3 K miles. There is a statistical curve here with the expected higher and lower results. As to horsepower, I think 1999 is not necessarily correct in his assumption. In my experience looser engines may use somewhat more oil and make a tad more hp than overly tight engines. Neither he nor I have any empirical evidence to support our impressions. As for me, as you might expect, I am somewhere in the above range at 9000 miles. Consumption has dropped slightly over the last 5000 miles. I have had compression and leak down done and had the bores scoped. My engine tests new/strong. Do not use an out of spec oil because it is reported that Variocam needs the specified range to function properly. If you are troubled go to the dealer but don't expect much sympathy unless you are in the 600-750 mpqt range. At some point they will monitor the situation if warranted ( unfortunately they make this decision). You can call 1800porsche for customer support if you think the dealer is blowing you off here. Do drive you car as a sports car and change the oil more often than is recommended. Good luck and enjoy.

 

When I know what the correct answer is, why would I change my postings? I'm not running for public office where I need to say what people are looking to hear. I only post what I believe to be true, whether it's popular belief or not.

So, if your car burned 9.5 gallons of oil every 15,000 miles, would you believe it was ok and not damaging your engine or performance? I mean, Porsche thinks it is ok.

As for a looser engine providing more hp....if the looseness is in the pistons, any gain from less friction is more than offset with blowby and loss of oxygen volume in the cylinders.

 

I am old enough to remember the Kawasaki 500 two strokes smoking (quite literally) the competition in the 70's. Were they tight? no. Did they burn oil? yesiree. Were they fast? youbetcha. As I remember they used exactly 9.5 gals of oil every 15,000miles. And thats all I got to say about dat.

 

Yup, and the bike was designed to burn oil....the Porsche is not.

 

We have now gone full circle. Reread your owners manual under oil consumption. Please post empirical, accepted data to support your beliefs regarding unapproved viscosity oils and low horsepower Porsche engines. Dyno a few motors and get back to me. Thanks

 

Empirical and accepted data was submitted to the wolrd in the 13th century from the wolrd's best scientists that the world was flat. Does that mean it really is?

You still haven't answered my question regarding being able to accept burning 9.5 gallons of oil in YOUR Porsche every 15,000 miles. Am I to asume that you are ok with that and it does nothing to damage the engine or lower performance?

I guess if you have no expereince or ability to know better, you have to accept what is forced fed you in life as being the right thing.....a marketer's dream.

That which is accepted is only right until a better answer is found.

 

My 997S has about 21000 miles on it over 2 years and is used as a daily driver with frequent short trips. It was broken in by the book and is run up to high rpm's regularly, including coasting down in lower gears. Modifications include: complete exhaust system, airbox, plenum & reflash. The oil, Mobil1 0W40, was changed 3 times. Consumption has been steady at about 1 quart per 2000 miles, after initial break-in. I take care now to only add oil when the indicator is down 2 bars, so as not to overfill.

Would I prefer that it consumed no oil? Yes. Can I tolerate it the way it is? Also, yes. Do I want to get in long, involved discussions about the philosophy of oil usage? No.