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Most of us on here use straight olive oil. It’s pretty cheap at costco. Olive oil also has a very high smoke point. Lots of threads on rennlist about this idea. You just need to search about it. I have been leaning towards using the virgin branded options. I to am reluctant to follow the Porsche owners manual. I think they are in bed with big oil.
I think 5W40 is the preferred weight for those that live in the heat, but some even go with 10W40. (In warmer environments, you want the first number to be higher, which indicates viscosity when cold.)
Most of us on here use straight olive oil. It’s pretty cheap at costco. Olive oil also has a very high smoke point. Lots of threads on rennlist about this idea. You just need to search about it. I have been leaning towards using the virgin branded options. I to am reluctant to follow the Porsche owners manual. I think they are in bed with big oil.
What is the best oil for an AZ car to deal with the heat. I am reluctant to use the recommended oil, IO think it may be too thin.
My opinion - I would absolutely avoid using the standard Porsche recommended viscosity in your area (high ambient heat levels in Arizona) - which is 0w 40. That oil will thin out and shear, providing you with unsatisfactory levels of protection. (You can verify this with UOA testing.)
The Porsche A40 standard shows that Mobil 1 FS X2 5w 50 is approved for use in the 991. Also - Mobil 1 FS X1 5w 40 is approved. The 5w 50 may be the better option, depending on how hard the car is driven.
I always thought that the purpose of multi-viscosity oil was that the oil automatically changes its thickness with the ambient temperature.
Why would a 0-40 not perform the same way as a 5-40 in extreme heat. Do they both not achieve the same "40" thickness at high temperature? Or, is a 0-40 oil high ambient temperature deficient?
@rmoudry If you are concerned with heat and going to drive the car hard (track), you can use Mobil 1 FS X2 5W 50. Although Porsche recommended Mobil 1 FS X2 0W 40 should be adequate. There are lots of oil test, results and discussions in the list. You just stepped on to a key board jockeys land mind. Porsche Manual should be your main source of information.
I always thought that the purpose of multi-viscosity oil was that the oil automatically changes its thickness with the ambient temperature.
Why would a 0-40 not perform the same way as a 5-40 in extreme heat. Do they both not achieve the same "40" thickness at high temperature? Or, is a 0-40 oil high ambient temperature deficient?
I will appreciate your responses.
As mentioned on many previous threads: upon starting the car, the 5W40 or 10W40 will "stick" to the cold engine parts better, whereas the 0W40 will tend to "run off" the engine parts more easily. If yolu live in cooler climates, the 0W40 is probably preferred, as too much viscosity upon starting the car is not desirable. If you live in warmer climates, the 5W40 or 10W40 may be preferable, as it won't be too thin when you start the car.
M1 5W50 works great in these cars. My Blackstone reports are better than ever. I use it year round in NY. Local NAPA has it in stock. My Blackstone reports with M1 and Motul 40 weight were not as good.
It is approved down to -13f by Porsche.
Last edited by AdamSanta85; 01-28-2023 at 12:56 PM.
I always thought that the purpose of multi-viscosity oil was that the oil automatically changes its thickness with the ambient temperature.
Why would a 0-40 not perform the same way as a 5-40 in extreme heat. Do they both not achieve the same "40" thickness at high temperature? Or, is a 0-40 oil high ambient temperature deficient?
I will appreciate your responses.
Lots of discussion over time on the 997 forum regarding the consistent loss of viscosity during use with Mobil 1 0w 40 (shown via UOA reports.) Some reports showing that significant viscosity loss occurred in as little as 1,500 miles of use.
If in doubt, you may want to conduct your own testing using Blackstone Labs or another source for used oil analysis testing. The reports will reveal the real story.
01-27-2023, 03:34 PM
