Engine Oil for 2001 986

[911monty]

I also live in California and since it never gets below ~20 deg 0W-40 is not required. I ran M1 0W-40 for one change and did not like the startup clatter. 5W-40 or 10W-40 from now on.

[lkchris]

With Mobil 1 last time I checked the Porsche oil is 0W-40 European Formula. "Formula M" in contrast describes oil meant for Mercedes diesels.

In any event, the oil should include "Meets Porsche A40" printed on the container.

In addition, there is zero advantage to 10W-40 versus 0W-40 in any conditions.

[78F350]

Originally Posted by lkchris

...
In addition, there is zero advantage to 10W-40 versus 0W-40 in any conditions.

You might as well be saying, "Zero is a better number than Ten." unless you have facts to back it up or personal experience to quantify it. Not saying you are wrong, just that I see no basis for your statement.

[911monty]

Originally Posted by lkchris

In addition, there is zero advantage to 10W-40 versus 0W-40 in any conditions.

Oh then try the inverse. Since I live where the temps I drive in are 50 to 100 deg f. there is zero advantage to running 0W anything. In fact my Owners manual states 5W-40, 10W-40 and 15W-40 are recommended.

However If you read Lubrizols ( major developers of Viscosity Modifiers)papers on the subject you will find that the 0W oils start with a 10 or less viscosity base stock, then through the use of long chain polymeric modifiers increase the viscosity to 30W 0r 40W. Since there is the potential that the molecular chains can be sheared and reduce the oil viscosity and since I drive in a lot of 90 degree temps, I choose to have a higher viscosity base stock to begin with.

I attempted to not start another oil war by saying the oil is not REQUIRED and only related my experience with 0W-40.

I'll add a few links for some reading.

A simple primer:

http://www.machinerylubrication.com/Read/1327/viscosity-index-improvers

Link to Lubrizol

http://hddeo.com/ViscosityModifierPart2.html

There is certainly much info on the subject eg Bob's the Oil Guy. I don't profess to be the authority, I just don't follow the crowd. I do my own research and use my best judgement. YMMV

[Slate 01]

Okay, I think I am totally confused. I was curious because I was running Porsche spec'd 10/40W Mobil 1. Now Walmart is selling 0/40W Mobil 1 (Porsche spec'd) for a heck of a price (5 gal for $22.58, okay I'm a cheap bastardo always looking for a deal). My oil is changed every 3 to 4K miles. So with winter approaching (if you want to call it winter in California) I thought getting an oil that gets less thick as it cools, should I really be that concerned.

So, should I be a cheap bastardo under my particular circumstances ?

[911monty]

Originally Posted by Slate 01

Okay, I think I am totally confused. I was curious because I was running Porsche spec'd 10/40W Mobil 1. Now Walmart is selling 0/40W Mobil 1 (Porsche spec'd) for a heck of a price (5 gal for $22.58, okay I'm a cheap bastardo always looking for a deal). My oil is changed every 3 to 4K miles. So with winter approaching (if you want to call it winter in California) I thought getting an oil that gets less thick as it cools, should I really be that concerned.

So, should I be a cheap bastardo under my particular circumstances ?

These are my opinions only! The oil commercials are somewhat misleading when they state 0 viscosity oil gets there quicker on startup. Let me throw this out there. The oil pump in your engine is a POSITIVE DISPLACEMENT gear pump, hence the need for an oil pressure relief valve. This means that for each revolution of the pump a precise volume is moved unless there is blockage, then the relief valve opens preventing overpressure and damage. This also means that any viscosity oil that can flow without the relief valve opening will arrive at the exact same time. Since we live in temps where the relief valve is not likely to open IMO 0W is not REQUIRED, If you wish to run it is also ok. Now if you live where you're starting your car @ 0 and below then it is required.

[newBgeek]

I can't believe that people are still getting this wrong. The viscosity of an oil at operating temperature is always the higher number. The 5W or 0W is only the winter rating or viscosity as 0 degrees Celsius. Even youtube car "experts" get this wrong.

ALL oils are thicker when cold, though ideally they should be a consistent viscosity at any temperature.

Originally Posted by 911monty

However If you read Lubrizols ( major developers of Viscosity Modifiers)papers on the subject you will find that the 0W oils start with a 10 or less viscosity base stock, then through the use of long chain polymeric modifiers increase the viscosity to 30W 0r 40W.

This is true with conventional oil, but synthetic base oils are inherently multi-grade and don't need friction modifiers (link to reference)

Bottom line is look at the back of the bottle for the Porsche A40 spec. If it's there, you are good to go, otherwise use at your own risk. Note that formulations change all the time, so oils previously having the Porsche A40 rating may no longer be approved. For example, the Mobil1 15W50 oil which was Porsche A40 rated a couple months ago is no longer approved in favor of the new 5W50 oil. There are no 10W40 oils that are on the Porsche approved list.

[Slate 01]

Originally Posted by newBgeek

I can't believe that people are still getting this wrong. The viscosity of an oil at operating temperature is always the higher number. The 5W or 0W is only the winter rating or viscosity as 0 degrees Celsius. Even youtube car "experts" get this wrong.

ALL oils are thicker when cold, though ideally they should be a consistent viscosity at any temper


This is true with conventional oil, but synthetic base oils are inherently multi-grade and don't need friction modifiers (link to reference)

Bottom line is look at the back of the bottle for the Porsche A40 spec. If it's there, you are good to go, otherwise use at your own risk. Note that formulations change all the time, so oils previously having the Porsche A40 rating may no longer be approved. For example, the Mobil1 15W50 oil which was Porsche A40 rated a couple months ago is no longer approved in favor of the new 5W50 oil. There are no 10W40 oils that are on the Porsche approved list.

Very interesting, thanks for the input. What a confusing subject on what seems to be a straight forward issue.

[10/10ths]

...lies within:

https://www.amazon.com/Joe-Gibbs-Driven-Racing-Synthetic/dp/B0095FBP5U