A tale of 2 charts

[friendly_jacek]

Originally Posted By: KCJeep
If that quote was accurate how come GM was so slow to get on the 20 grade bandwagon then I wonder?


because they built bad engines that required good oils?

 

[fdcg27]

Originally Posted By: chrisri
That doesn't change the fact that every engine should wear less with Euro 40 grade than with 20 grade SN stuff...
What would be real life difference is another matter.


You just spitballin', or you have something to back this up?

 

[slacktide_bitog]

Originally Posted By: chrisri
That doesn't change the fact that every engine should wear less with Euro 40 grade than with 20 grade SN stuff...
What would be real life difference is another matter.


Not necessarily since most wear occurs at startup, where the first number matters more. 5w20, 5w30, 5w40 virtually no difference.

A 0w20 would most likely have less wear than a 5w40, right?

 

[aquariuscsm]

Originally Posted By: slacktide_bitog
Not necessarily since most wear occurs at startup, where the first number matters more. 5w20, 5w30, 5w40 virtually no difference.

A 0w20 would most likely have less wear than a 5w40, right?


That's false. No such thing as "start up wear". You'll notice now it's being called "warm up wear",which has nothing to do with the oil (the parts are already oiled) but the internals of the engine are at their perfect "mesh" when it's at optimum operating temperature. If you run 0W20 in a HP car that specs 5W40 (and drive it accordingly),you'll probably be shopping for a new engine.

Anyway,that's my take and understanding on it.

 

[Shannow]

Originally Posted By: slacktide_bitog
Not necessarily since most wear occurs at startup, where the first number matters more. 5w20, 5w30, 5w40 virtually no difference.

A 0w20 would most likely have less wear than a 5w40, right?


Nope, there are those on the board that perpetuate that myth as it suits their agenda...the Industry standard test has full oil pressure/flow, and holds the oil at a sub-optimal temperature for additive function.

I started a conversation on the topic, whcih has some good input from Bobby Davro and others

http://www.bobistheoilguy.com/forums/ubb...on.#Post3680194

 

[chrisri]

Originally Posted By: fdcg27
Originally Posted By: chrisri
That doesn't change the fact that every engine should wear less with Euro 40 grade than with 20 grade SN stuff...
What would be real life difference is another matter.


You just spitballin', or you have something to back this up?


I can give you examples, so you and others can pull out your own conclusions.
What I said previously was that 0/5w40 oil will protect any engine better than 0/5w20 SN oil. Both grades have similar cold flow properties, so cold start are not an issue here. Mainly difference comes with engine operating at normal and higher temperatures. Higher HT-HS of 40 grade protect bearings, valvetrain and cylinders/pistons. And BTW, most of the cold wear appears in cylinders/pistons and valvetrain, not because of oil, but because of chemical processes in cold engine. Any grade oil will protect similar in normal ambient temp. if we stay within grades designed for given area.
I agree that for NA users SN resource conserving oil is adequate, but I also think that Euro oil would still do it's job better without any drawbacks.

According to Lubrizol comparison tool A3/B4 is superior in every way to a SN oil, except fuel economy requirements.
Ford of Europe recommended A5/B5 oils (under 3.5 HTHS), but they clearly state that using of A3B4 is not an issue.
Mazda of Europe recommends for their modern diesels use of C2 (under 3.5 HTHS) and C3 oils which are over 3.5 HTHS.
On ACEA site they clearly say for A1/B1, A5/B5, C1, C2 specification that they are UNSUITABLE for some engines. All of those are superior to SN oil,according to Lubrizol.
For A3/B4 they simply say; high performance oil suitable for all modern engines.
I could never find any car manufacturer that recommends over 3.5 HTHS for normal use will allow use of thinner oil in any circumstances. I gave two examples for opposite recommendations.

 

[Shannow]

Originally Posted By: fdcg27
Originally Posted By: chrisri
That doesn't change the fact that every engine should wear less with Euro 40 grade than with 20 grade SN stuff...
What would be real life difference is another matter.


You just spitballin', or you have something to back this up?


Adding some spit to the ball...

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1064688&page=1

and a google books link

Not supportive of the blanket statement, but when viscosity can't keep the parts apart, then additives come into play, and bearing materials become sacrificial (over the long term, no pile of failed engines today).

 

[Shannow]

Originally Posted By: friendly_jacek
Originally Posted By: KCJeep
If that quote was accurate how come GM was so slow to get on the 20 grade bandwagon then I wonder?


because they built bad engines that required good oils?


Some support for that statement.

 

[chrisri]

Originally Posted By: Shannow
Originally Posted By: fdcg27
Originally Posted By: chrisri
That doesn't change the fact that every engine should wear less with Euro 40 grade than with 20 grade SN stuff...
What would be real life difference is another matter.


You just spitballin', or you have something to back this up?


Adding some spit to the ball...

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1064688&page=1

and a google books link

Not supportive of the blanket statement, but when viscosity can't keep the parts apart, then additives come into play, and bearing materials become sacrificial (over the long term, no pile of failed engines today).



Great post Shannow , dynamic viscosity and stable, shear resistant base oils are IMO most important part that protects engine from wear. Oils designed bh Euro specs have to retain its starting HTHS even after 20k of use. This was main reason ACEA organization was founded years back. Old formulas would share after 20k KM OCI that was common over here in early 90s before ACEA came to the scene.

 

[OVERKILL]

Originally Posted By: chrisri
Originally Posted By: Shannow
Originally Posted By: fdcg27
Originally Posted By: chrisri
That doesn't change the fact that every engine should wear less with Euro 40 grade than with 20 grade SN stuff...
What would be real life difference is another matter.


You just spitballin', or you have something to back this up?


Adding some spit to the ball...

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1064688&page=1

and a google books link

Not supportive of the blanket statement, but when viscosity can't keep the parts apart, then additives come into play, and bearing materials become sacrificial (over the long term, no pile of failed engines today).



Great post Shannow , dynamic viscosity and stable, shear resistant base oils are IMO most important part that protects engine from wear. Oils designed bh Euro specs have to retain its starting HTHS even after 20k of use. This was main reason ACEA organization was founded years back. Old formulas would share after 20k KM OCI that was common over here in early 90s before ACEA came to the scene.


It isn't the base oils that shear, but rather the VII's. Better base oils allow the use of less VII's and subsequently result in a more shear stable product (over simplifying a bit of course).

 

[A_Harman]

Originally Posted By: friendly_jacek
Originally Posted By: KCJeep
If that quote was accurate how come GM was so slow to get on the 20 grade bandwagon then I wonder?


because they built bad engines that required good oils?


More like, they could meet CAFE standards without using 20-grade oil. Why spend the money to re-engineer 4 million production engines a year if you don't have to?