ADias

Why are you still in this forum #!tching about this, instead of enjoying your Vette?

RonnieTheC

I am on this forum for the same reason that I am many forums...to keep up with what folks have to say about their cars. And yes, i am completely enjoying my Vette.

hockeyguy

It's too bad you got a lemon engine.
I think the variability may be increased by being more hand-built vs completely automated.

As a musician, it reminds me of Steinway grand pianos, among the best in the world, all hand built...but some real lemons emerge...unlike, for example, Yamaha pianos, automated build, all good and equal quality, but none great or special.

simsgw

Well, we are like that. Engineers never feel like wasting time on something that isn't a technical problem. For any other sort of problem, check the Yellow Pages. Are there no counselors? No therapists? No Chevy dealers left in the world?

In this case, we have an engine designed to be one of the best in the world by the engineering team that helps design a good 20% of the world's cars. It is not designed to be like those from "any other manufacturer" and it is not. One of the design trade-offs is the type of owner it will suit, and that's the case with everything we engineers build, whether it's going to the industry trades or consumer retail.

This is not a car for everyone. No one at PCA will care that a Porsche behaves as the engineers predicted it would behave. I don't.

Now as to whether this particular trait differs between 997 dot ones and twos... that's a different comment I'll direct to people who own Porsches.

Gary

simsgw

Not only new to them, but in a real sense, they may not be suited to enthusiast cars of any type.

I don't feel like typing another version of a comment elsewhere, but I'm not sure how to link to another thread. I'll try this way:

In post #43 of "Too much oil on factory fill" I gave my opinion of why Porsche do not care any more than I do how many people complain about oil consumption. And why, unless they are just satisfying an itch to bitch, it indicates those people should be driving something else. Perhaps a Chevy.

In post #37 of that same thread I had offered one example of how controlling a design (and its production line) for the best in performance traits can cause a non-performance issue like consumables to vary widely among examples. I've read other informed guesses that are just as likely to be true. I don't really care which reason is true, and I have no hope of us outsiders seeing something that the thousand engineers at Zuffenhausen somehow overlooked. I suspect that to whatever extent management has pressed the engineers to reduce the production-line variation of this trait, it is just a nuisance to them. In my opinion, and I surmise in theirs, no real Porsche enthusiast gives a damn how often he adds oil. It is part of what Porsche owners do. And always have.

I mean seriously now, people. We spend entire days scrubbing and polishing and basically nurturing these devices. I could eat lunch off the disk brakes of one guy in our local club. People less healthy, like Cindy and I, spend money on detailers that amounts to as much as an oil change. And we spend for that item much more often.

Should Marvin be upset that he must check the oil level at each fuel stop and add a quart every other time? It just gives him a chance to open the engine cover and wipe off the annoying dust while the oil flows in. Should I worry about spending an extra penny a mile on consumables when I spend so much on people to clean the car?

Enthusiasts do not. Others need to learn enthusiasm or buy cars where an important design requirement is "not being a nuisance to the driver." No exotic is that sort of car and none ever will be.

Gary, an enthusiast

RonnieTheC

I guess that I am not an enthusiast because I have chosen to drive a Corvette that does not require 1 quart of oil every 500 miles rather than a Porsche that does. But was I an enthusiast when I owned 2 Ferraris? Maybe a Ferrari is not considered an exotic because they don't, in my experience, have an important design requirement that is a nuisance to me. Never had a problem with my 360 or F430. Never added oil. Oh well.

Fahrer

This is getting as bad as the BMW forums.

It is not heresy to question a design aspect of your favorite car. I almost got tarred and feathered at Bimmerfest ( figuratively) because I pointed out some boneheaded design apects of my 535.

My 911 is fantastic but even Porsches are not perfect!...... and I am definitely not a Corvette guy.

Chris from Cali

I've had very little oil consumption in my 997.2 vs my 997.1 (2-3 qts in 10K+ miles vs. 6-7 qts in 10K miles). Most of that was in the first 5-6K miles. My RS4 consumed a LOT more than either of them (and interestingly, that was DFI too).

Bob Rouleau

I wonder about a lot of things.

1) My dealer overfilled the oil at both oil changes. I wonder if too much oil increases consumption as a result of foaming. Adding oil to bring the level back to too full will result in very high consumption.

2) Break in - does oil consumption vary based on whether the car was broken in by the book or following a different regimen?

3) Someone mentioned short trips. My daily commute is about 30 minutes each way and at speeds of around 50 MPH. This is enough to gt the oil warmed. Short trips might promote higher oil consumption.

4) Did PAG compromise on oil consumption versus fuel consumption? Perhaps the rings were tweaked for lower friction and better fuel economy as Macster hinted?

That being said, my 997.2 C4S PDK does not burn oil between changes at 6,000 mile intervals. That includes 5 track days when I drove the snot out of it.

Best,

simsgw

If it were truly overfilled, you wouldn't have foaming. This isn't a wet sump engine where too high a level causes crankshaft immersion and splashing. I've forgotten what it does do... someone will remind us I'm sure. But it isn't trivial. The oil gets places it should never be and you can damage the engine.

What you probably saw is the upper half-bar lit on the LED display. I interpret that as full, having designed a few such displays myself, but dealers are clearly not sure themselves or are just sick of arguing with owners who rightly interpret the awkward wording in the manual to mean roughly "Aaaaghhh! I've overfilled the oil!" when they see that lit up.

If that's all it was, I wouldn't worry at all, Bob. My upper half bar has been illuminated since we bought the car. When I first saw it, and checked the manual, I asked the mechanic to manually check the oil level with me. It was correct. He wasn't sure why that bar lights up, just that "it always does when we add the correct amount of oil" but I was sure as soon as I confirmed the physical oil level. It's just one of those classic computer display conundrums and this is one possible answer. People want to read a discrete bar like that as if it were an analog display and it isn't. The only real choice is which sort of confusion you decide to cause.

Yes.

Darned if I know, but it sure isn't good for the engine in other respects.

No. It can't be that or any other explanation that would create a condition that applies to all examples. If we care what it is, other than a simple trait of the Porsche engines, then we need an explanation that would create the wide range of behavior we see across the examples built in the same period.

My point exactly. It isn't a lot of oil being consumed when it does happen; it is being consumed, not leaking and collecting somewhere unseen as happened with one notorious design in the past; and it doesn't happen to all the engines, so it isn't a common design trait directly causing the problem, if we consider it one.

DFI certainly has nothing to do with it directly, and if it had an indirect effect -- that is, if some other change like the increased compression ratio is involved -- then we need some production line variation to explain why so many examples use no measurable amounts of oil. Like yours and mine and many others.

Gary

JSeven

My 997.2 has almost 11.000Km on it and zero oil consumption.

J.Seven