slicky rick

there will be two sides to this one of course the consumers and non consumers. i think what we should try to analyze is more what is causing this differential. reason for this is if we can gather al the good minds and find out why then maybe the people who consume oil could better substatiate a claim to allow them face up to porsche and say there is something wrong. if its the rings then i think there should be a recall on this one...my fear is we have to face the fact that there are incidences of oil consumption whihc means its a reality. some of us might not experience this yet but who knows after the warranty period it pops its ugly head what then? some are lucky to have the problem now while their cars have warranty...lets solve this abnormality.

todd.

If you bother to acknowledge others in this "community" beyond the 5 people you claim to know, you'd realize there IS an oil consumption issue with the 997.2.
I've owned three 997.1's, none of which needed more than a sip of oil the first couple thousand miles. My 997.2 went through 3.5 quarts the first 2500 miles.

mdrums

Once again...my 06 and 07 Carrera S and my 2000 and 2001 BoxsterS did not burn oil. Even at the track these cars did not burn much if any oil.
My 2009 Carrera S will burn oil like a 2 stroke engine on the street or track...not much difference.

wwest

DFI engines allow a higher compression ratio than has been generally available in the past, ~12:1 with DFI vs ~10:1 otherwise. Might that alone result in a higher level of oil consumption..?? Especially for engines that are more often driven HARD..??

Macster

Not directly, but perhaps indirectly.

A higher compression ratio will result in more blow by and increase the contamination rate of the oil. The pre-DFI Porsche engines (except those turbo-charged) came with an 11.3:1 (IIRC) compression ratio.

Now this can have an effect on oil consumption cause as the oil becomes more contaminated it becomes more fluid. Thus the oil is more likely to exit the engine through the various paths available to it.

One of these is past the rings. Primarly the oil consumption arises from the reduced ring tension and perhaps smaller thinner oil control rings. This is intended to reduce internal engine friction.

It does this, but allows more oil past the rings into the combustion chamber where it is of course consumed (or expelled along with exhaust gases).

Another possibility is because the oil is more fluid it tends to aerate more readily. (The added water and fuel levels work to accelerate the depletion of the anti-foaming additive package in the oil.) This has the result of increasing the amount of oil in the crankcase air. The AOS (air/oil separator) is overwhelmed and some of this oil is directed to the intake manifold and the engine where it is burned. Smoking upon startup can be one sign this is occurring.

Aeration can be compounded by if the oil accumulates a good load of water and unburned fuel the oil level rises. This subjects the oil to more foaming/frothing and more aeration which increases oil consumption.

Sincerely,

Macster.

rijowysock

wow, great response..

i never have smoke on startup, only white smoke ive ever seen is on WOT right after kickdown, pretty much the instant the oil pressure gauge peg's 5.

stevepow

I think I went through 3 qts (or was it two?) in the 1st 3K miles, and after oil change only one quart in 2K miles. Seems pretty random, although I do drive the car harder now that it is through the break-in period - I'm sure that is not unique.

ADias

I wonder if those who experience oil consumption tend to drive consistently short distances and accumulate water. That does not explain all high-oil usage cases, but it could explain plenty.

What some forum members appear to have difficulty in accepting is that every gen of boxer engines has used oil. This is not new. Some claim there are more reports recently with DFI cars... not my observation. What I think is going on is that in recent years many new owners are new to Porsche and this is new to them.

ADias

Good luck. Are you going to recall all oil consuming 911 boxer engines since 1964? This is not new.

These days there's a tendency to demand that everything is perfect and use political force over companies - watch the Toyota onslaught. The Porsche boxer engine is exceptional but not perfect. It can use some oil. Get used to it, or buy a Honda.

ADias

Todd: There's no more oil consumption in the 9A1 engine than there was on the M97 or the M96, and on and on... You got previous 997s with little oil usage and many other people did, along many others who use oil - talk to Edgy01.

The other thing is that most cars out there have very few miles... oil usage in boxer engines improves with miles - good miles, open road, high RPM, miles.

RonnieTheC

Porsche is not interested in claims or in cars that consume what is, for any other manufacturer, a huge amount of oil. That is why, in the owners manual for the 997.2 it states that 1.6 quarts every 622 miles is acceptable consumption. This is absoutely nuts! My new 09 used 1 quart every 500 miles. And I drove 5900 miles in the first 4 months of ownership. (the car is gone...my new Vette burns zero oil). I went to mediation and arbritration against Porsche North America, and the bottom line is that they just do not give a sh*t if one's $109,000.00 car uses one drop less that 1.6 quarts in 622 miles. I don't think it makes any difference as to what causes this crazy consumption because Porsche will not do anything to correct the problem. Why? Because they do not see it as a porblem. So much for German engineering...it's all hype.

fjpdds

14000 miles plus, 1 year ownership on 2009 S. Burns oil at consistent rate. Dealership says within Porsche acceptable levels.
2007 GT3 burns zero oil.

Edgy01

If you went into arbitration--who was the independent arbitrator? Porsche can't be the arbitrator.

OldGuy

Mine used a qt. in the first 2000 miles, None since (09C2SPDK)

todd.

That I agree with you on, since changing my oil at 2500 miles the consumption has improved dramatically.