Need Some Guidance for my 1.8T

[Audi Junkie]

Originally Posted By: Audi Junkie

I can show you temps where 5w-40 is twice as thick as 5w-30, and at that cool temp you are saying 2000cSt is better than 1000cSt or 500?

 

[BobFout]

Originally Posted By: Audi Junkie
Originally Posted By: Audi Junkie

I can show you temps where 5w-40 is twice as thick as 5w-30, and at that cool temp you are saying 2000cSt is better than 1000cSt or 500?


You used a viscosity calculator to determine this? Or actual viscosity measurement?

 

[Audi Junkie]

Sounds like you are questioning the technique rather than the facts.

Twice as thick is a pretty blunt fact, but you disagree, based on what? Do you have any ~numbers~ of your own?

 

[BobFout]

Originally Posted By: Audi Junkie
Sounds like you are questioning the technique rather than the facts.

Twice as thick is a pretty blunt fact, but you disagree, based on what? Do you have any ~numbers~ of your own?


What oil temp are those viscos for?

I am trying to get more information to see if the technique (and therefor the results) should be questioned or not.

(For those watching at home, we know about viscosity calculation validity much below 0C)

 

[Gary Allan]

What's his take on it? Grossly inaccurate to heavier or lighter? I don't have the mojo to pick it apart or support it.

Here's another one


and here's an interesting conversion utility


People smarter than myself made these things. Smarter people can subject them to critical review.

 

[Audi Junkie]

Don't overthink it.

It's a thick oil vs a thin oil.

Are you surprised the thick oil is thicker when cold?

 

[Thermo1223]

I'm saying what you don't seem to fathom is it is of little consequence. If operating temp protection is his main concern and it is still considered 5w when cold whats the difference?

He will not seize his turbo unless he abuses the car which no oil will prevent. He wanted to know what the best protection would be and since warranty is of no concern. He could use GC 0w30 but for less he could get the same with T6.

BTW your recommended a 0w...since that's what euro's use right?

Would you be surprised to know the approved Mobil that would have been used under warranty 0w40 is just as thick at 40c as T6 but his engine wouldn't survive right? So it stands to reason that along the same lines as Castrol blurs the 30w line with GC, Shell blurs the 5w line with T6 or maybe Mobil blurs the 0w line with 0w40? You decide....

AFE 0w30 is the one you should have recommended if cold flow was that important since it is significantly thinner or maybe PU 5w30 which is way down there. Then again I like a HTHS closer to 3.5 in a turbo-charged engine myself and I don't consider running a 5w synthetic in the winter to be a problem regardless of the operating viscosity.

 

[Audi Junkie]

AFE 0w-30 is only an A1 oil, not A5, which makes it a dino oil in my book.

AFE is thicker than PP 5w-30 at any temp that can be demonstrated.

Major skip.

 

[JAG]

Originally Posted By: Audi Junkie
AFE 0w-30 is only an A1 oil, not A5, which makes it a dino oil in my book.

The ACEA gas and light diesel specs have been combined so there is no such thing as just A1. It would be interesting to know why they don't state it meets ACEA A5/B5. There could be multiple reasons that are not valid reasons to avoid it.

Quote:
AFE is thicker than PP 5w-30 at any temp that can be demonstrated.

How can AFE be 0W-30 while PP 5W-30 is 5W-30?

 

[Audi Junkie]

Run it thru the visc calc.

M1 AFE
Viscosity, ASTM D 445
cSt @ 40ºC 63.1
cSt @ 100ºC 11.0

PP 5w-30
Viscosity, ASTM D 445
cSt @ 40ºC 57.5
cSt @ 100ºC 10.3

http://widman.biz/English/Calculators/Graph.html

 

[JAG]

I understand that. I was asking how can you explain the viscosity classifications of those oils given what the viscosity calculators predict.

 

[Audi Junkie]

M1 oils tend to shear, other than that I dunno exactly how they design it to meet spec.

On that note, I does seem odd that an "AFE" product would be so thick at op temp anyway.

I'll take a thinner A5 oil for the same money anyway.

 

[JAG]

I think M1 AFE is a highly non-Newtonian fluid (viscosity drops as shear rate increases) which would explain it's low HTHS viscosity relative to its not-so-low KV @ 100C viscosity. I'd choose many other oils over it too. But it has some happy users.

 

[BobFout]

Originally Posted By: BobFout
Originally Posted By: Audi Junkie
Sounds like you are questioning the technique rather than the facts.

Twice as thick is a pretty blunt fact, but you disagree, based on what? Do you have any ~numbers~ of your own?


What oil temp are those viscos for?

I am trying to get more information to see if the technique (and therefor the results) should be questioned or not.

(For those watching at home, we know about viscosity calculation validity much below 0C)


Here is what I was alluding to with this post.

This is a PM convo between myself and widman a few months ago. (I have the permission of both parties involved to post this publicly)

Code:
Me: How accurate is your visco calculator from -20C to 100C?



Widman: With most oils it should be accurate until you factor pour point modifiers



Me: Hm OK, how would a PP modifier affect the visco calculator results?



Widman: It flattens out the expected results at low temperatures.