[IridiumRS400]

bottom line, 20w oil is fine. run 30w if it tickles your pickle and makes you feel "safe", but dont use 40w oil. thats extremely outdated thinking applied to a modern engine and oils.

You're going to love this discussion - right in your wheelhouse...

Thin vs Thick Discussion, Chapter 10

 

[IridiumRS400]

Heard in other discussions that dark is not indication that it is bad. I don't know the science behind it though. I have seen different brands go dark much quicker than others. I have not used the color as any type of gauge for changing the oil.

Dark oil w/DI engines is due, in part, to soot from combustion that is in suspension in the oil.

 

[IridiumRS400]

The one thing I have always wanted to know is how a direct injection engine which dilutes the oil with excess fuel can make a difference in the choice made. This is probably a reason why people use 5w30 instead?

Yes, especially when you see your UOA results where you start out with a 5W30 viscosity and its shears down a grade.

And I know there's been much to be said about "But 0W20 is the spec oil for a VR30DDTT..." to which I will point to Section 10-2 of my 2017 Q60 Owner's Manual:

It reads "As an alternative to this recommended oil, SAE 5W-30 conventional petroleum oils may be used and meet all specifications and requirements necessary to maintain the INFINITI new vehicle limited warranty."

Can't honestly say why they quote "conventional" vs "synthetic" but, w/e...

 

[IridiumRS400]

While I don't doubt your statement, dark oil occurs in many engines old and new. The Project Farm guy exposes the oil to just heat and it turns all of them darker and many of them to a near black color similar to what I see on the stick on most of my cars shortly after an oil change.

Agreed, that why said "In part", as is the nature of DI and a small % of incomplete combustion (soot) which washes down the cylinders into the oil.

 

[IridiumRS400]

That line was deliberately removed from the owners manual in 2018 and all subsequent years.

Yes, and if Infiniti was that hard-over about NOT using 5W30, I would thought they would have sent out an addendum to the '17 Owner's Manual with a replacement 10-2 page deleting Note 3.

 

[IridiumRS400]

I know you specifically stated “my 2017 Q60 Owner's Manual” which is true statement. I just didn’t want someone with a 18+ to be unintentionally mislead into believing their owners manual states the same thing.

Yup, my MY2017 Q60S is the unicorn of unicorns - a VR30 w/5W30 in the crankcase AND original turbos (w/EGTs!!!), and daily driving with a 1.3 bar Ecutek map.

Living dangerously...

 

[IridiumRS400]

18.85 PSI

LOL - to my credit, in most cases, when I post "1.3 bar", I typically also state in psi as ~19 psi for non-math types

One of the few instances I can use the "~" symbol.

 

[IridiumRS400]

They did however look at me like deer in headlights when I brought up the optional shorter dipstick and extra oil.

Not surprised... the shorter dipstick is akin to the secret handshake, er, fist bump...