snarf

Thanks for the feed back, to summarize since resurrecting this thread:

Oil consumption in miles/litre

2 @ 2000 - 3000
4 @ 4000 - 5000
2 @ 11000 - 12000

mdrums

WOW, why are you all using so much oil?

cgng30

I added 1/2 a quart at 1000 miles, changed oil at 2000, havent added oil since then. i now have 5000 miles. Althought I noticed that the oil level changes on the bar depending on the ambient temp, dont ask me how, but I saw it my self. few day it was in the low 30 s and I checked the oil level in the car it showed low, wtf, when i was in the car, when i got out of the car it was normal. in warmer temp like 50-60 the level is perfect with me in or out of the car so I did not add any oil, and yes the car was level in my garage, same refrence point.

snarf

Curious about thermal expansion of Mobil 1 I was searching a Mobil web site for data when I came across this in an answer to a BMW driver's question about drain intervals.

"It is also not uncommon for a high-performance engine to require a top-up of motor oil every 2,000 miles. (Most manufacturers consider anything better than 1,000 miles between top-ups as "normal.")" The full Q&A can be found at http://www.mobiloil.com/USA-English/..._in_a_BMW.aspx

Now back to my search for the thermal expansion coefficient. BTW using the thermal expansion coefficient for Benzene (I have no idea how relevant to Mobil 1 this is) a 9 litre volume at 20 degrees C would increase/reduce by 0.11 litres per 10 degree C increase/reduction in temperature. For this reason we should all fill up our fuel tanks just before dawn, because fuel is sold by volume not weight we will get more for our money when the temperature drops.

Frino

6,000 miles since 5/06. 3/4th of a quart of oil added. Drive it hard every day. More or less followed factory break in. Still loving every minute behind the wheel.

roberga

41,000 miles track it often uses zero oil. Same bar level when I take it in for an oil change as when I drove away from the last.

500

Automobile Magazine long term test car (05 997 S) with approx. 18,000 hard miles and only two quarts...

Mike Murphy

My 120,000 mile '88 Carrera uses no oil. But even if it starts to use 1qt for every 1000 miles, I won't care too much. Some of these cars use oil, some don't. Some use a lot. But if it's within spec (follow the manual), then it's in spec. Don't worry about it.

Mike Murphy

Snarf, I was wondering what you found when researching the thermal expansion coefficient. In some other threads I am part of, some techs are saying that oil doesn't expand (noticeably). Others are saying that it does. Anyone with experienced with oil in regards to how much it expands/contracts due to temperature?

Mike Murphy

I found this online at http://www.chevron.com/products/prod...fuel_perf.shtm

Coefficient of Thermal Expansion:
Liquids increase in volume as their temperatures increase. The coefficient of thermal expansion is a measure of the rate of volume increase with temperature. A typical value for the coefficient of thermal expansion of kerosene-type jet fuel is 0.00099 per degree Celsius [(ºC)–1] [(0.00055ºF)–1]. At this rate, one gallon of jet fuel will expand 4.0 percent for an increase in temperature of 40ºC [1.000 gallon at 0ºC (32ºF): 1.040 gallon at 40ºC (104ºF)].
Of course, the relationship is reversible. For example, as jet fuel cools in the aircraft’s tanks during flight, it will occupy a smaller volume than it did on the ground. The coefficient of thermal expansion can be used to calculate the volume decrease.

rcg412

Doug - 15w50 was factory fill and is mentioned as the recommended oil in the Porsche 996 Owners manual, US version MY99, MY00, and MY03 . See renntech for the MY03 version. I have not seen the other 996 years so do not know if that is the case.

Wonder how much Mobil paid for Porsche to exclusively tout the benefits of 0w40!?!?! Ross

Doug Hillary

Hi,
rcg412 - well, I can find no evidence that a 15w-50 oil was EVER a factory fill in any Porsche engine made since August 1992 (Technical Bulletin 9213 dated November 3 1992). In this Bulletin it advised that "All engines produced in Stuttgart-Zuffenhausen from August 1992 are now factory filled with SAE5w-40 synthetic oil."
I believe it was a Shell product - a forerunner to Shell Helix Ultra!

If you have evidence that a 15w-50 oil was EVER a factory fill after the late 1980s, please publish the details,
I would like to update my records with this information and so would others!!

In Porsche's "Technische Information (911) 1701 Group 1 No 1/99" (dated 28/01/1999) the following information was provided;

1 - 235 Factory Approved engine lubricants were Listed

2 - Of the 235 Approved/Listed lubricants;
170 were fully synthetic
65 were semi-synthetic
No Mineral oils were listed

3 - Viscosities of the Approved oils follows;
0w-30 - 3 (all fully synthetic, Polar use only) #
5w-30 - 11 (8 fully synthetic & 3 semi synthetic, Polar use only)#

0w-40 - 19 (all fully synthetic)
5w-40 - 118 (113 fully synthetic & 5 semi synthetic)

10w-40 - 63 (57 semi synthetic & 5 fully synthetic)##

5w-50 - 15 (all fully synthetic)###
10w-50 - 5 (all fully synthetic)####

10w-60 - 2 (Castrol fully synthetic products)*

No 15w-50 oils were listed and have not been for some years. Even Shell Helix Ultra 15w-50 fully synthetic oil, which has BMW and Ferrari Approvals and has been marketed around the World for well over a decade was not Approved. Their 5w-40 version was and is!

In Approving and Listing these oils Porsche had to consider not only the quality of the oil but general availability as well. Some oils were available World wide (WW) and specific to other such diverse markets as Dominican Republic, Morocco, Russia (etc) and specific Asian markets

By the time the next Bulletin was issued many oils had been de-listed and the total was halved - as follows;

# - SAE30 oils fail to meet Porsche's HTHS 150C minimum viscosity criteria. No SAE30 lubricants are Approved or Listed by Porsche today (except for use in the Cayenne V6 where VW503.00 quality standard is required)
## - This viscosity range has been primarily superceded by 5w-40. It was once the most popular oil in Europe hence its 1999 listing
### - Some of these oils probably had difficulty in meeting Porsche's, some were cross branded products. Only Mobil 5w-50 is Approved and Listed today
#### - This viscosity range is now effectively obsolete
* I assisted with the initial development of this lubricant in the late 1970s and early 1980s

Handbook recommendations are always superceded by Technical Bulletins in the case of Porsche and in the case of all other engine manufacturers too

In engine development, VW-Audi-MAN and BMW use Castrol, MB and some others use Mobil and Ferrari and others use Shell. Developing engines and components is now so costly and some components are so complex it makes great sense to collaborate with suppliers. CAT uses Mobil and so does DD-MTU-MB-VM probably the largest manufacturer of mid to large high speed diesel engines

For instance Castrol's development programme with VW-Audi includes field testing protocols that take several years to reach conclusions from. This is quite normal practice

Regards

1999Porsche911

You're looking at the wrong TSB's. There was in fact, 15W50 on the approved list. It is even approved in the manual. The 99's were on the road long before date of the TSB you quote. As for proving that 15W50 was the factory fill. My car hit the road in early 1998 and was filled with 15W50.

Doug Hillary

Hello,
1999porsche911- as usual I will request again that you provide the "correct" TSBs so that we can all digest the data

The Drivers Manual only shows a viscosity reference chart

In the TSB data (911 Carrera (996)/911 Carrera 4 (996) I referred to, the viscosity chart DOES NOT list or refer to a 15w-50 lubricant. This data was retrospective for all 4,6 and 8 cylinder engines built from 1973!

Please post the TSB data you refer to and any information concerning the Factory's fill!

Thanks

1999Porsche911

All I can tell you is to read all the oil tsb's issued, it states the 15W50 quite clearly on the early ones. You can read all the TSB's at ALLDATA.