Logic behind using 0W30 in a 0W20 vehicle

[Leo99]

Originally Posted By: userfriendly
The thread title is "Logic behind using 0W30 in a 0W20 vehicle". I can't see the logic of using 0W anything unless it is colder than -30C outside and, without a block heater plugged in.

Is there instead; "logic behind using 5W20, 10W20 or SAE 20 in a 0W20 vehicle"?


I think the logic is "thicker is better".

 

[pbm]

...So which flows better at 0*F...Mobil 1 0w30 or a typical (syn. or dino) 5w20?

 

[CR94]

Originally Posted By: pbm
...So which flows better at 0*F...Mobil 1 0w30 or a typical (syn. or dino) 5w20?
That depends on the meaning of "better" you choose to assume. Both should flow well enough to protect an engine.

 

[dblshock]

til this all plays out go a grade or two heavy, couple years we'll see specs back at 5//30 5w40 where your not sacrificing the equipment to save a stupid 1.5%

 

[JHZR2]

Originally Posted By: Shannow


Your statement, your proof..

You stated that the 5W30 shears down to a 20...your statement...defend it....



Originally Posted By: Nickdfresh
Quote:
And are you saying that 20s DON'T lose viscosity in service ?


Strawman? Can you hear me?


How is it a strawman ?

YOU stated that the 30s become 20s in service....what happens to the 20s then ?

If your logic is that 20s are fine because 30s become 20s, then what becomes of the 20s becomes a pertinent point.

Again, not my statement to defend...it was yours.


I agree that a fuel diluted 20wt could be a concern, granted Ive seen those and its not that bad in terms of viscosity. Im not yet concerned that a sheared 20wt oil is a big concern these days.

IIRC, one of the arguments early on in the 2000's wave of 20wt oil specs, was that the typical (at the time) conventional 5w30 would shear to the high end of the 20wt range, while the new 20wt specs tended to produce a lube that was in the more viscous end of the 20wt range, with better specified shear stability (which drove to other base stocks, etc).

Meanwhile, cross the manufacturing element. Bearing clearances have changed little over the years but the asperities have been minimized allowing thinner oils to be used.

 

[dblshock]

...and if Mr. Peabody brow beats you like that with his [censored] just go one grade up til we sort it out.

 

[dblshock]

very little error margin in a 0/20, avoid it.

 

[Shannow]

Originally Posted By: JHZR2
I agree that a fuel diluted 20wt could be a concern, granted Ive seen those and its not that bad in terms of viscosity. Im not yet concerned that a sheared 20wt oil is a big concern these days.

IIRC, one of the arguments early on in the 2000's wave of 20wt oil specs, was that the typical (at the time) conventional 5w30 would shear to the high end of the 20wt range, while the new 20wt specs tended to produce a lube that was in the more viscous end of the 20wt range, with better specified shear stability (which drove to other base stocks, etc).

Meanwhile, cross the manufacturing element. Bearing clearances have changed little over the years but the asperities have been minimized allowing thinner oils to be used.


If you recall also at the time, the 20s ALWAYS stayed in grade, as the grade at the bottom end was ridiculously low, based on the original method of "time through a viscometer" of defining grades.

Fixing that with the introduction of 16, 12, and 8 has seen lots of 20s out of grade, and mostly fuel diluted as you suggest...boundary additives and polymeric coatings are the new world, replacing hydrodynamics for much on a bearing's life.

 

[dblshock]

and if you love 0/20 just have the engine rebuilt at 80k, so what.

 

[Jetronic]

Originally Posted By: dblshock
nothing worse than another sheeple adding a qt. of 0/20 1200mi. into his OCI.


Cars with such a consumption get a new engine under warranty, or get scrapped, here in Europe. I doubt you'll get it through the inspection anyway. Leaks aswell as poor combustion will get you a ban.

 

[UltrafanUK]

It's very rare for a modern engine to fail if the owner has it correctly maintained (Cam belt system in particular), BUT many owners give up after the warranty expires cos the valve guide oil seals and rings are bad enough to cause a high oil consumption. Some of that ring wear can be caused by thin oil issues.
Some engines (Mostly TDI's), also suffer from using Xw30, rather than Xw40 grades in cam lobe wear terms.

Oddly enough, running out of oil is still a popular way to trash a modern engine, as not many OEM's fit oil level warning lights. A low oil pressure light does not give enough warning at high power when you run out of oil, as many older VW TDI owners have found out.

 

[Jetronic]

Those are beyond saving even with an oil level indicator. An engine low an oil starts to run audibly different long before the low pressure warning kicks in.

Same deal with TPMS. A lot of owners happily ignore the warning and destroy tyres in the proces.

 

[4WD]

Dave: great example on how to be assertive (good) in place of aggressive (bad). !

 

[Nickdfresh]

Originally Posted By: Shannow
Originally Posted By: Nickdfresh
BTW, what is that based on?


https://bobistheoilguy.com/forums/ubbthreads.php/topics/4220561/Re:_Viscosity_Index._When_is_t#Post4220561

chart (cherrypicked obviously), has name of the source on it.


Here's just a couple of UOA's on the front page. This 0W-20 with nearly 8K is a 9.0cst while this 5w30 in a 2.7L Ford is 8.69...

Both cherrypicked as well. Obviously not every XW-30 oil shears all the way down to a XW-20. But most do shear, and XW-20 syns seem to hold up very well overall...

The MaxLife Full Syn held up better here, but still isn't that much thicker at 9.47cst than the 0W-20...

These are just cursory and assume that the labs did good work...

 

[Nickdfresh]

Originally Posted By: UltrafanUK
It's very rare for a modern engine to fail if the owner has it correctly maintained (Cam belt system in particular), BUT many owners give up after the warranty expires cos the valve guide oil seals and rings are bad enough to cause a high oil consumption. Some of that ring wear can be caused by thin oil issues.
Some engines (Mostly TDI's), also suffer from using Xw30, rather than Xw40 grades in cam lobe wear terms.

Oddly enough, running out of oil is still a popular way to trash a modern engine, as not many OEM's fit oil level warning lights. A low oil pressure light does not give enough warning at high power when you run out of oil, as many older VW TDI owners have found out.


I agree, but it does happen. A year ago or so I talked to a guy in a mall pub that was waiting for his wife to pick him up after his 14' VW GTi grenaded. I asked him if he did his own oil changes, he said he did. I tried to be subtle but said something to the affect that I hope he used the appropriate VW50x.xx oil. He claimed he used either Mobil 1 or Castrol SYNTEC 0W/5W-40 and that there was a stealth bulletin regarding timing chains on them AFAIK...

 

[Nickdfresh]

Originally Posted By: Jetronic
Originally Posted By: dblshock
nothing worse than another sheeple adding a qt. of 0/20 1200mi. into his OCI.


Cars with such a consumption get a new engine under warranty, or get scrapped, here in Europe. I doubt you'll get it through the inspection anyway. Leaks aswell as poor combustion will get you a ban.


And it doesn't actually happen. Just sheeple trolling on about anecdotes that are rarely seen here...

 

[fdcg27]

I don't know how things are on the island that may or may not soon leave the EU, but here engines fresh out of warranty generally don't show either valve guide seal or ring wear to any extent.
We've had engines in both new and used cars that exceeded or at least approached 200K in our ownership that never used any appreciable amount of oil, even those that saw the relatively thin 5w30 grade from new.
The logic of the 0W-20 grade is that it does allow for easier starting in very cold weather, which we see in much of this country. It also allows for better fuel economy in the first minutes after a cold start as well as all of the time for those vehicles that are mostly short-tripped.
There is the same Chicken Little talk about the adoption of 0W-20 as there was thirty years ago when 5w30 began to be the recommended all-climate grade for a number of GM models. The sky didn't fall then and probably won't now.

 

[Nickdfresh]

Originally Posted By: fdcg27
...
There is the same Chicken Little talk about the adoption of 0W-20 as there was thirty years ago when 5w30 began to be the recommended all-climate grade for a number of GM models. The sky didn't fall then and probably won't now.


Exactly. Only twenty years ago one still had (then, older) recommendations for some cars where 5w30 was "not recommended for sustained high speed driving."

 

[demarpaint]

Originally Posted By: fdcg27
I don't know how things are on the island that may or may not soon leave the EU, but here engines fresh out of warranty generally don't show either valve guide seal or ring wear to any extent.
We've had engines in both new and used cars that exceeded or at least approached 200K in our ownership that never used any appreciable amount of oil, even those that saw the relatively thin 5w30 grade from new.
The logic of the 0W-20 grade is that it does allow for easier starting in very cold weather, which we see in much of this country. It also allows for better fuel economy in the first minutes after a cold start as well as all of the time for those vehicles that are mostly short-tripped.
There is the same Chicken Little talk about the adoption of 0W-20 as there was thirty years ago when 5w30 began to be the recommended all-climate grade for a number of GM models. The sky didn't fall then and probably won't now.


There's something a bit different now regarding some vehicles. Looking at an owners manual from over 30 years ago they left the oil selection up to the owner to decide, based on climate and how the vehicle was to be used. I have owners manuals from Ford from 1984, 1985, 1987, and 1988. Some of the owners manuals for vehicles driven today are one size fits all, no matter what. Food for thought. But as you said the sky didn't fall then, and probably won't fall now.

Me I like choices.

 

[4WD]

And too many OEM are now pushing a brand - we have enough marketing bull without that ...