Do Manufacturers Assume Loss of Grade?

Originally Posted by UncleDave
Of course. Thats call figured into the OCI and recommended grade.

The hysteria around 20 grade is amusing because many have been effectively driving around with sheared and diluted 20 that started at a 30- for decades.

UD

Hysteria....nailed it. It's so funny.
 
Originally Posted by redbone3
I believe VW specs 5-40 on my Passat because in a 10K OCI it shears down to a lower viscosity.

What approval does your VW require and what is the viscosity retention requirement for that approval?
 
I've only had one change with VW 502 00 approval 5W40s stay in-grade beyond ~5K miles.

oil_TBN_viscosity.JPG
 
Originally Posted by TiGeo
I've only had one change with VW 502 00 approval 5W40s stay in-grade beyond ~5K miles.


Which is somewhat by design. What matters is the HTHS, most 502 oils are hardly 40 grade to begin with.
 
Originally Posted by JohnnyJohnson
LOL they don't assume anything you bought it and now its your problem!


lol.gif


As soon as you buy a new car, it's value is sheared (or is it diluted) by %10 plus all the other fees, taxes, etc.
shocked2.gif

Compared to that shearing from xW30 to xW29, 28, 27, .... and eventually xW20 (a defined SAE Viscosity Grade) is not a huge problem
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Originally Posted by Gene K

Do manufacturers assume a one grade loss in use?


They don't care. They only have two objectives.

Objective 1: MEET CAFE
Objective 2: Last long enough to get comfortably past warranty.
 
Originally Posted by TiGeo
Originally Posted by UncleDave
Of course. Thats call figured into the OCI and recommended grade.

The hysteria around 20 grade is amusing because many have been effectively driving around with sheared and diluted 20 that started at a 30- for decades.

UD

Hysteria....nailed it. It's so funny.


+1 So true. LOL
 
Originally Posted by PWMDMD
Gene K said:
[quote=PWMDMD

I think BITOGers, in general, try too hard to dissect out the nuance in oil choice that 99% of the time makes no appreciable difference. It really doesn't have to be any harder than following the manual for grade, certs and OCI. Then again, if we just did that, half of all posts here could be deleted.


BOOM!

Being an oil related forum, yeah probably.
 
Originally Posted by Triple_Se7en
Objective 3: Profiteering


Oil viscosity choice does not factor in the profitibility of auto companies. The average auto buyer barely cares about oil or its viscosity. Many don't even know what "viscosity" even means.
 
Originally Posted by PWMDMD
Originally Posted by Gene K
Originally Posted by PWMDMD
Like most things oil...does it really matter as long as it meets specs going in and it's changed at an appropriate OCI? This forum has plenty of UOAs with significant fuel dilution, low to out of grade viscosities and no apparent issues with the engine.


So your saying the manufacturer picked the grade by flipping a coin?


I'm saying whatever their reason for one grade or another have you ever seen definitive proof it really matters? How many "discussions" do we suffer through on here with respect to "Oh my God engine X used to be spec'd for 5W-30 and now purely because of CAFE it's spec'd for 0W-20 and the sky is falling". Then mile after mile and UOA after UOA life goes on seemingly without any issues.

I think BITOGers, in general, try too hard to dissect out the nuance in oil choice that 99% of the time makes no appreciable difference. It really doesn't have to be any harder than following the manual for grade, certs and OCI. Then again, if we just did that, half of all posts here could be deleted.

My thoughts on 95% of what is on BITOG.
 
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