If 0w-20 in the winter why not 5w30 in the summer

[Shannow]

Originally Posted By: bigj_16
That "Minimum Oil Film Thickness" you are pointing to is the tail end of the wedge. That has nothing to do with the oil weight you are using.


It IS the definition of "Minimum Oil Film Thickness" in the engineering sense...the bearing design sense...It would appear that you are not versed in the engineering side of things to deny same...

Here's the engineering design charts, that we used pre CFD...note that this is journal bearings, and it's MINIMUM OIL FILM THICKNESS versus bearing parameters


the X Axis is (r/c)^2 (radius on clearance) times viscosity times speed divided by specific pressure...change one and trace with your finger the direction that MOFT goes with each variable...

As to your statement about viscosity and MOFT...if you do the above, you can see it's plain wrong...

Here's an FE calculated Rod bearing for different viscosities and speeds...


Clearly, more viscosity, more MOFT...just like the universal laws of physics say that there will be.

 

[SilverFusion2010]

Need popcorn...

 

[Shannow]

Originally Posted By: SilverFusion2010
Need popcorn...


Need the ability to replay the last 15 years of bearing design discussions...

 

[JoelB]

Let me ask you this Shannow. Do you run thicker oils than the manufacturer recommends in your vehicles? How do you determine what is thick enough? If thicker really is better then isn't something like a 10w60 the most ideal oil? And since it isn't clear over text I'm curious about your thoughts, not being snarky.

 

[SR5]

Originally Posted By: JoelB
Let me ask you this Shannow. Do you run thicker oils than the manufacturer recommends in your vehicles? How do you determine what is thick enough? If thicker really is better then isn't something like a 10w60 the most ideal oil? And since it isn't clear over text I'm curious about your thoughts, not being snarky.

Shannow can easily speak for himself, but since I'm here.

For his Supercharged V6 (Buick engine) the OEM spec in Australia is 15W40, but Shannow runs a Euro 5W30 A3/B4 with a HTHS of 3.6 cP. Still thicker than an ILSAC 30 grade (~ 3.0 cP) but less than a typical 15W40 (~ 4.0 cP).

For his newer cars under warranty, it would be strictly by the book.

 

[SilverFusion2010]

30 grade is the goldilocks viscosity for most gasoline engines. CAFE regulations pushed the auto manufacturers to look at oil viscosity as a potential source of MPGs.

And most of the time 20 is enough for a daily driver. If you plan to push the engine hard, going thicker a grade or two may be necessary for optimal protection.

The reason that owners manuals are calling out thinner and thinner oils is also CAFE regulations. To get their fuel economy credit they are required to recommend the grade of oil they tested with.

 

[4ever4d]

Discussions here seem to be that each camp is wrong. Too thin or too thick. The conclusion is somewhere in the "middle" I tend to believe. We never speak of the middle ground. It always seems to be to the extreme on way or the other, to the point of getting down right ugly sometimes. Can't we all just get along.

 

[SilverFusion2010]

Originally Posted By: 4ever4d
Discussions here seem to be that each camp is wrong. Too thin or too thick. The conclusion is somewhere in the "middle" I tend to believe. We never speak of the middle ground. It always seems to be to the extreme on way or the other, to the point of getting down right ugly sometimes. Can't we all just get along.

Did you read my post?

 

[4ever4d]

Originally Posted By: SilverFusion2010
Originally Posted By: 4ever4d
Discussions here seem to be that each camp is wrong. Too thin or too thick. The conclusion is somewhere in the "middle" I tend to believe. We never speak of the middle ground. It always seems to be to the extreme on way or the other, to the point of getting down right ugly sometimes. Can't we all just get along.

Did you read my post?

Yes i did. I agree with you, yet the extreme(ism), if you will, continues on.

 

[dblshock]

I want a high SASP oil and all the popular grades are realitivly thin at temp anyway.

 

[BrocLuno]

0W-20 winter and 5W-30 summer sounds good to me (for some motors)

 

[Shannow]

Originally Posted By: JoelB
Let me ask you this Shannow. Do you run thicker oils than the manufacturer recommends in your vehicles?


Nope...30 years ago, I'd add a can of STP to my 20W50 (20W50 was as per the manual for nearly everything in Oz)...

My Caprice, mentioned by SR5, is specced per the manual at 20W50, with 15W40 for "prolonged operation in snow conditions"...It's got an ACEA A3/B4 5W30 in it.

My old Nissan Navara ZD30 was specced at 15W40, I ran 5W40, 0W40 (*), and ultimately 5W30 A3/B4, maybe bolstered a bit.

Wife's Captiva is specced for 5W40 C3, which is sort of what it's got in at present, holds 6L, so when it starts getting regular OCIs, will have a C3/Dexos 2 5W30, and the balance of the change something a bit heavier at additive treat rate levels.

Colorado is specced at 5W30 Dexos 2...that's what it gets under warranty...

Originally Posted By: JoelB
How do you determine what is thick enough?


Given all of what I've presented above, with regard to MOFT, CAFE oils only push film thickness in the wrong direction...they know it...the OEMs know it and the like.

Grade per se is meaningless, HTHS is what matters in the bearing surfaces (cams and boundary lubricated stuff are additive dependent), so I work on that.

3.6 to 3.8/3.9 is about where I typically want my HTHS...take the Nissan, the specced 15W40 should have been around the 4.2 mark, going synthetic, and 5W40 (note, I don't need the 5W part...ever), I dropped the operating viscosity into that range.

Using a bit of Nulon 25W60 as an "additive", I can bump the 3.5/3.6s up a little.

Originally Posted By: JoelB
If thicker really is better then isn't something like a 10w60 the most ideal oil? And since it isn't clear over text I'm curious about your thoughts, not being snarky.


Although that's the usual logical falicy presented (so if you say this, then you must mean THIS - insert overextreme example), I'll answer...if your OEM calls for that, then the "thinner flows more and would be better" argument that's been presented lately is plain wrong...if they call for a specific unicorn, and there's failures, use it.

Check my posts, I typically steer people away from even 20W50.

I don't NEED 0W, 5W, or 10W, so don't chase them...can't help it with synthetics, as that's what they are.

I don't favour wide grade spreads, I don't favour uber VI chasing, as "better" is the total package, not a single metric (to paraphrase one peanut with the chart below "while it lost 40% of it's viscosity, it's viscosity Index improved considerably")



Less plastic, less shear, less deposits, more room for oil and additive...if you NEED 0W, then you should use 0W.

I won't typically advise anyone to go to 50 grade for anything...won't advise them to got to 20. (except things like Redline, the original Mobil 1, and regular old 20W20, as their HTHS is what an actual "20" is, around 2.9+, as it's not a multigrade built to the HTHS mins for economy).

Guess that makes me "centrist", or "moderate", eh ???

When I present the science behind stuff, it's to demonstrate well known physical principals, that aren't the realm of the usual advertorial stuff that's prancied around...show that viscosity leads to larger MOFT, while also demonstrating that it wastes more energy in drag is a part of that, not demonstrating advocacy of the Oz oil manufacturer's penchant for 60s, 70s, and (alleged) 80s...

 

[nZone]

Experience with my car only: 2011 Acura MDX.

Recommended: 5w-20

On a hot summer day with 5w-20, say 90F+ degree, I can feel the engine heat radiates 1-2 feet away. The hood is hot to the touch. With the same ambient temp, but using 0w-40, there is no heat radiating and the hood is cool to the touch. The 0w-40 is way quieter and smoother. Engine noise is also reduced in the cabin at highway speed. However, 0w-40 is too thick in the NE winter. The 5w-20 is great for NE winter.

 

[tig1]

Originally Posted By: nZone
Experience with my car only: 2011 Acura MDX.

Recommended: 5w-20

On a hot summer day with 5w-20, say 90F+ degree, I can feel the engine heat radiates 1-2 feet away. The hood is hot to the touch. With the same ambient temp, but using 0w-40, there is no heat radiating and the hood is cool to the touch. The 0w-40 is way quieter and smoother. Engine noise is also reduced in the cabin at highway speed. However, 0w-40 is too thick in the NE winter. The 5w-20 is great for NE winter.





On a 90F day heat radiates from the hood using 5-20, but with 0-40 there is no heat radiating from the hood. IT"S A MIRACLE!!!!!

 

[nZone]

Originally Posted By: tig1
Originally Posted By: nZone
Experience with my car only: 2011 Acura MDX.

Recommended: 5w-20

On a hot summer day with 5w-20, say 90F+ degree, I can feel the engine heat radiates 1-2 feet away. The hood is hot to the touch. With the same ambient temp, but using 0w-40, there is no heat radiating and the hood is cool to the touch. The 0w-40 is way quieter and smoother. Engine noise is also reduced in the cabin at highway speed. However, 0w-40 is too thick in the NE winter. The 5w-20 is great for NE winter.





On a 90F day heat radiates from the hood using 5-20, but with 0-40 there is no heat radiating from the hood. IT"S A MIRACLE!!!!!


Yes, it is a MIRACLE if you put it that way.

 

[coffee]

Originally Posted By: Rolla07
Originally Posted By: T-Stick
So we all know that the industry is moving to 0w20 ... but if that is the right weight for a winter viscosity why would not a lightweight (energy conserving) 5w30 be just as suitable or better in the heat of summer.


Why cant people accept that 0w20 is perfectly effective year around regardless of where you live, for daily driving?


Amen!

 

[T-Stick]

The point of thread is not whether 20 weight is "effective" but whether it is "optimum" in the summer in comparison to a 5w30.

 

[kschachn]

Originally Posted By: nZone
Experience with my car only: 2011 Acura MDX.

Recommended: 5w-20

On a hot summer day with 5w-20, say 90F+ degree, I can feel the engine heat radiates 1-2 feet away. The hood is hot to the touch. With the same ambient temp, but using 0w-40, there is no heat radiating and the hood is cool to the touch. The 0w-40 is way quieter and smoother. Engine noise is also reduced in the cabin at highway speed. However, 0w-40 is too thick in the NE winter. The 5w-20 is great for NE winter.

So 0W-40 causes there to be less heat produced from the combustion of the gasoline? If not, I wonder where that rejected heat is going? Up your...? No, probably not. I think the hot air only comes out, not goes in.

You and the "hand to manifold" test guy should get together. You aren't him, are you?

 

[igs]

Originally Posted By: kschachn
Originally Posted By: nZone
Experience with my car only: 2011 Acura MDX.

Recommended: 5w-20

On a hot summer day with 5w-20, say 90F+ degree, I can feel the engine heat radiates 1-2 feet away. The hood is hot to the touch. With the same ambient temp, but using 0w-40, there is no heat radiating and the hood is cool to the touch. The 0w-40 is way quieter and smoother. Engine noise is also reduced in the cabin at highway speed. However, 0w-40 is too thick in the NE winter. The 5w-20 is great for NE winter.

So 0W-40 causes there to be less heat produced from the combustion of the gasoline? If not, I wonder where that rejected heat is going? Up your...? No, probably not. I think the hot air only comes out, not goes in.

You and the "hand to manifold" test guy should get together. You aren't him, are you?


One of the basic functions of oil is to cool the engine.

 

[kschachn]

Originally Posted By: igs
One of the basic functions of oil is to cool the engine.

OK sure. And then put the heat where?