SilverSteel

In changing my oil, I've found it to be quite the challenge to find 0-40wt Mobil 1. Which I finally did at Walmart for $5.68 a qt. I wanted to buy the Gallon jug but couldn't find anyone who even carried the stuff. That said, I began to wonder, why 0-40wt? Well, I found this article that I believe will be interesting to Porsche owners. Have a read...

http://www.performanceoilnews.com/oi...nst_oils.shtml

Riad

Here's fantastic thread on the CGT forum, Doug Hillary does an amazing job explaining oil.

https://rennlist.com/forums/porsche-supercars-carrera-gt-918-960/249494-c-gt-oil-change.html

djantlive

The performance oil article suggests that Mobile 1 0-40 requires frequent oil changes but yields most HP. When I changed my oil at 10K mi, it still has another 5K mi to go based on the color of it (light brown only). This tells me that our engine and oil cooling is doing a great job in keeping the oil cool.

wross996tt

That about sums it up. Like reading War & Peace!

SilverSteel

I'd like to point out that I was unable to find metal chips, which are considered normal if they're small and few, as OCBen had in his oil. My 997 has 13k on it. I even ran a magnet through the oil with little results, most parts made from various hardened aluminums these days, no surprise. I removed 8.5 qts and replaced it with 9. Sure I could have had the dealer do it, but I wanted to see, smell and feel the oil.

ohsixx

Did my first change at 1007 miles.

snarf

It's not too surprising that particles are invisible to the naked eye a micron is a milionth of a metre - approximately 4 X 10^(-5) inch, so 20 micron is only 0.0008 inch (imagine a particle with a diameter of about a quarter of the thickness of a human hair). Sampling oil requires cycling the oil through a series of graduated filters for a period of time and then examinig these under a microscope.

wross996tt

Did you read the link the riad posted?

1999Porsche911

If your engine is prone to burning oil or leaking oil, it will be at it's worse with a 0W40 oil. These engines should not be running this low of a viscosity in moderate to high temperature regions. However, if you continue to prefer to follow Porsche's sugestion to use 0W40, then you can always fall back on the false beleif that "all flat sixes use oil", and live with the decreased performance of your engine due to blowby along with increased likelyhood of seal leakage. You may also experience additional valve noise in hot weather due to premature leakdown of oil using a 0W oil.

Absolute minimum oil viscosity in an engine that runs 210F+ is 5W50 if you truely care about performance and protection of the engine.

wross996tt

First off, the link suggests multiple times that you should use what is on Porsche's recommended list (0W40 or 5W40!)..so just say no to 10W40.

IBID

This is a good question...but I think oil consumption is more than just realted to oil viscocity. Probably a result of an interaction of factors including break-in, seals, environmental, driving habits, start-up and cool down process, etc. Are you talking about the oil "consumed" at start-up or during normal operation or at the track? Seems to me the oil is there to lubricate and cool. If it is being consumed there are other reasons IMHO.

1999Porsche911

Everyone always forgets one of the most important functions of engine oil...and that is to SEAL. The 0W40 DOES NOT seal as well when hot as a 5W50 and therefore, more oil will be lost to blowby with the 0W.

It's funny how many people will accept as normal, the burning of a quart of oil every 1000 miles, yet not change their drving habits and oil viscosity.

wross996tt

Just a clarification...according to TSB 1701 1/05 (7/28/05) only 0W40, 5W40 and 5W50 are approved by Porsche.

bgiere

M1 0w40 is a very capable oil...good enough to do 12-15,000 OCI's if you are so inclined...i can post used oil analysis reports if anyone has an interest in seeing them. The Carrera Cup series in Australia (really hot weather) is using a Fuchs Silkolene 0w20 with great success. Those engines are rebuilt more often of course, but the wear rates and tests show terrific protection. Oil that looks dirty means the oil is doing its job and keeping contaminants in suspension. FYI,there is absolutely no way to judge an oils suitability based on color. It has been proven many times over in many different climates and engine types that a heavier weight oil does not necessarily give better engine protection.

wross996tt

My bad...I have a 2004 manual...I would go with your info. since it is more up to date...The TSB is the most current data for my car. In either case there is no 10W40 approved.

Brant, BTW I agree completely!

1999Porsche911

That TSB shows that 5W50 IS approved.