Bruce In Philly

I find this odd.... I am using less oil as the car ages. 2009 C2S 57K miles

I purchased the car with 26K miles.... I don't have an exact figure, but it used more oil that any car I ever had. IIRC, it was about 2 - 2.5 quarts in 10K. I was actually a bit worried. Now it is less than half that at 1 quart every 7K miles.... (I change my oil every 7K now).

I know you use less oil but that is up to break in..... 26K miles the engine should have been broken in. Whazzup with this?

Peace
Bruce in Philly

Robocop305

I noticed the same thing. I started using less oil as the car ages. I currently have 35k miles..

ogun228

Same here.Used 1 qt per 2500 miles since bought in Nov '13 with 19k miles. Oil change at 25k and since full bars.

tomc66

You need to take the car up to red line a few times. This helps to seat the rings.

yashagrawal

Same here, bought 4 year old c4s with 8000 miles, initially consumed 1 quart per 2500 miles, now at 15000 miles about 0.5 quart per 2500 miles.

Mumbles

Had my 09 c2s since 2k miles, its now at 11k and uses less oil than it previously did throughout the past year. Very noticeable indeed

LexVan

All very normal comments and observations. You can see from consistent UOAs that engines are still breaking in at well over 20,000 miles.

Macster

Actually high RPMs do not help seat the rings and can lead to ring damage if the rings are not broken in enough.

This is why Porsche advises keeping RPMs during break in.

What helps seats the rings is load. Avoid lugging the engine but give the engine some throttle at lower RPMs and in higher gears.

Do this at varying RPMs. This creates the most pressure in the cylinders and forces the rings out against the walls with more pressure.

This helps the rings wear in and form a better seal with the cylinder walls and also the ring groove walls in the piston.

Macster

Assuming you haven't changed your style of driving or oil change intervals, oil viscosities/brands and the oil consumption monitoring has been consistent this is not surprising.

Lab and field tests have found engines continue to break in for many more miles than their nominal break in miles.

As they continue to break in they run cooler -- less internal friction -- and deliver better gas mileage.

Oil consumption can go down though maybe not because the rings are sealing better and allowing less oil past into the combustion chamber, but because the rings are allowing less blow by which means less oil vapor creation which means the AOS has less oil vapor to deal with and less oil leaves the engine through the AOS.

j beede

According to Porsche you probably are losing oil--but it is being replaced by condensed water vapor, coolant, windshield washer solution :-), gasoline, or other fluids. I suppose an oil analysis is the way to go if you want a definitive answer.

If your oil level really is increasing, you may have come up with an entirely new concept for "synthetic oil".

kellen

So should my car be making oil with 105k???

ADias

Easy to check - drive 50/100 miles and keep revs high (3k+) and all the spurious stuff in the oil will evaporate. At the end of the run you will have the correct oil level.

Another point - when changing oil it is best NOT to fill to the top bar (in the oil gauge). Keep it down 1 bar or 2 to prevent overfilling. Especially if you often drive short distances and incorporate gas/water in the oil.

gpjli2

This was my problem. Over time and with increasing miles oil began to overflow. Result: ruined garage floor. Had to sell car and buy new one.

Philster

This.

Wasserkühlung

Yup! I am 120k miles now and worked out a deal with Shell to purchase my overflow. Lol


Last 3k miles I have used zero oil since switching to M1 5-50. I was using about .5 quarts every 3k miles with the M1 0-40. Like the Metzgar engines I believe these engines just start getting broken-in at 100k.