drmarkp

Fact is that level of consumption can hide some serious problems. Mine used much less than that and needed new engine at 7500 miles due to scored bore (the sooty exhaust on one side was what worried me). In last 10,000 miles on new engine it hasn't needed a drop - and it goes better. I know which end of the consumption range I prefer. And race engines are different - less rings for starters (I think!)

gpjli2

Hello Mark. Glad you are loving that engine. I remember your postings on Roadfly. Fact is that there were problems with the rings within a certain production range (late05/early06 prod?) thus the scored cylinder barrel. Porsche was aware of this. Damage to the cylinder was the cause of your symptoms including the uneven pipes and oil use. Must be great to get a new motor but most cars using moderate amts of oil are fine and run up to snuff. Interestingly mine (3/05 prod) showed uneven soot pattern. For me, bore scope was negative. As oil consumption dropped with milage, pipes evened out. Still getting better at 12K miles. Runs really well. Hard to say when an owner should be concerned but I do think this new"standard" is ridiculous. Gerry

911Dave

Actually it's not my theory. Traditionally, engine break-in is a critical period that can affect how well the engine ultimately performs (compression), how long it lasts (wear), as well as oil consumption.

The main idea is that the primary concern in engine break-in is the seating of the piston rings against the cylinder walls. If the seal isn't done properly, combustion gases can blow by the rings and pressurize the engine's crankcase. This, in turn, forces oil vapor to exit through the crankcase breather.

The general consensus in the Porsche community is that following established break-in procedures isn't all that important with our cars. I have no idea if it is or not, but I suspect there's a considerable variation in how Rennlist members have broken in their cars. Some followed Porsche's 2,000 mile procedures to the letter, others drove it like they stole it from day 1. Most have been somewhere in the middle, based on all the comments I've read. I'm sure most engines are broken in well, but there's bound to be a lot that aren't.

uzj100

What? You're supposed to drive them? I'm saving mine for the next guy

gab997

I have 7500 miles on mine. I had the oil changed at the 1500 mile mark, tracked the car twice and only added less than half a quart.

cello

Dave, while I agree with you on break in, it really does not explain the "wide variance in consumption between the listers that responded to Dan's survey" and that is the problem. It may be a partial explanation, relevant to some circumstances more than others, but as no two break in procedures are ever identical, that cannot explain the "wide" variance (not that you intended your response to do so). So, the pregnant question is: What is causing the large variance in oil consumption. There may be several answers, acting independent or in concert: Built in tolerances or protection, manufacturing defect, user error/misuse, or the ethereal "high performance engines are not built the same way as a typical car engine". However, there should be a primary reason and THAT Porsche should know and that knowledge should be shared. My car has not burned a drop since 1500 miles.

kauai_diver

How and where we drive on a daily basis also contributes to varying oil consumption.

Craig T.

I have a 997S with 4,200 miles. I've tracked it once, and my wife uses it a s a daily driver. When I pulled out of a steep driveway last week the "check oil level" came on. It was only 1/2 qt down. It must have been the steep descent. Still 1/2 qt in 4,200 miles seems about normal.

Edgy01

I believe that we can take the owner's role out of the equation. I have spoken with several boxer motor owners (from 996 TT to Boxster) and some have told me that they also got terrible oil mileage,--on the order of 1 quart per thousand. Yet, with a different late model Porsche, they are back to normal consumption rates. Did they suddenly change the way they drive?

Clearly this is a complex issue or Porsche would have solved it long ago.

gpjli2

The stock answer is that it is a boxer motor and they all do that. Tell that to Subaru. One would think it comes down to metalurgy and tolerances, issues that should be within the control of this manufacturer. I can say that the onboard computer monitors all aspects of engine performance that Porsche feels are important. It does not monitor oil consumption.

Edgy01

Are Subaru big oil users?

gpjli2

Never known one to use a drop but I've only had 3 and am acquainted w a few others. I think it has to do with random factors, ie the way the parts come out of the parts bin. As a high performance motor maybe it does need different tolerances than a standard motor. Some motors will just by chance end up with different overall tolerances than others. The real question is whether, except in extreme cases, it makes a difference in performance. I got the feeling that the Porsche techicians, not the dealer techs, did not think it to be a problem. They gave me a paper stating my engine showed no faults after they invested 6 hours of tech time at my request. My engine had sootier pipes on the left and at 1000 miles was using a qt in 1200 or so. It is now using a qt 3500-4000miles at 12000miles. Obviously the right bank had one or more cylinders burning more oil that the left bank. Now it is barely if at all noticeable. Made me crazy but they would never tell me to my face that there was any issue at all. A long breakin for a car that was not babied. Do I think that my car makes less power than one of the" non oil burners"? No It may be looser and make more for all I know. Anyone want to play with dynos?

gpjli2

Btw, I have been known to go down to local dealerships and stare at tailpipes for hours. My wife says that makes me really ****. Who should know better than her?

dgcate

I know of 2 of these engines in this town, that have used this kind of oil since brand new. That's not normal. Porsche couldn't sell this car to anyone, if it were... imo

gpk

gpjli2,

Sounds like our experience has been similar. I also have the sooting on the left side. The 5-6 quarts is correct, and while not the most extreme, it is a lot more than those saying they've never had to add a drop or maybe a half quart at best.

As to the potential buyer issue, when I show them my service receipts that indicate "the customer is complaining about excessive oil use", they may not buy the "Porsche said it's normal" line.

Consumption has seemed to moderate somewhat and I still have the soot on the left side. C'est la vie.