Optimal kinematic viscosity for mimimal wear?

[Junior]

Originally Posted By: Gary Allan
Quote:
I don't see a reason to use a lightweight oil unless you live in rigid cold weather. Do you guys really think you know more than the top engineers who design and test these (heavy-duty/high-performance) engines?!


Some of us see no benefit to heavier weight oils without a reason. None of us really thinks that we know more than the top engineers who design and test these heavy duty and performance engines.

Most of us don't drive truly heavy duty or performance engines, as much as we like to think so. Most of us who do, when engaged in truly heavy duty or high performance situations, follow the advice of those top engineers.

Quote:
Yep, they sure do have good engineers. But do you honestly think their goal is to spec an engine oil for the protection of the engine?


So I shouldn't listen to those good engineers, and only listen to good engineers that spec heavy oil?

Quote:
They just care about sales


I would hope that they leave that stuff to the marketing dept, but let be fair here, are you saying that engineers who spec heavy oils care less about sales? Buy it ..don't buy ..what do they care?

Quote:

I know you thin oil guys will call me ignorant and not knowledgeable, But.


I term it a bit biased due to lack of experience base.


Yeah, we engineers get blamed for everything. The truth is the vast majority of us do the best we can to meet the design criteria with the resources, time and cost targets we are given.

 

[Steve S]

When we talked to from the factory, they called it an E.F.U..

 

[Gary Allan]

Quote:
Remember if a 40 wt keeps the metal seperated as needed a 60 wt will not necessarily keep them apart more better.


Ah ..but if a 20 weight keeps metal parts separated, a 30 or 40 grade would be much mo-bettah? (begging for a light bulb of concession to just give one really dim flicker here ..one momentary faint feeble glow ..a glow of hope).

Quote:
oing up a steep grade isn't put your foot to the floor and pick the gear that will get you the fastest speed over the hill . I never mentioned that engines never are run at 100% did I ? Usually engines operate at a less than full throttle engine load most of the time.


Steve ..take any passenger car chassis ..and load it up to the power output:load ratio of your former big rig fully loaded ..and run it 60% of the time that way. It will take some conversions and some allowances ..but I don't think you would be using 0w-20 oil to eek out a few more mpg's. You would be factored to make the thing last in that type of service.

Nothing you said had anything to do with viscosity. It had to do with driver idiocy or intelligence. You could have just as easly said that you hammered the thing 100% of the time you drove it. It would still have nothing to do with why they spec 40 grades.

 

[FZ1]

See,I told you. Lol.

 

[BuickGN]

Originally Posted By: Gary Allan
Steve ..take any passenger car chassis ..and load it up to the power output:load ratio of your former big rig fully loaded ..and run it 60% of the time that way. It will take some conversions and some allowances ..but I don't think you would be using 0w-20 oil to eek out a few more mpg's. You would be factored to make the thing last in that type of service.



So going by this logic, are you admitting that some extra wear occurs in your automobile when run hard on a 20wt over a 40wt?

 

[SuperBusa]

Originally Posted By: ekpolk
Originally Posted By: SuperBusa
. . .
Obviously, the thinner oils still have enough film strength to protect Aunt Bea's 4 banger Corrola (which was designed to use thinner oil) while going back and forth to church and the bingo hall. But ol' drag master Jack isn't gonna like using Aunt Bea's oil in his top fuel dragster.

Oh I forgot this gem. Please show me where any of us who don't see "thin" oils as some form of evil have ever suggested that someone should run 0w-20 in a top fuel dragster. Let's keep it real now. . .

... dude, it's an example to get the point across. Did I say anyone suggested they run thin oil in a dragster?! ... you're more of a drama queen than ol' Gary is!

 

[Gary Allan]

Originally Posted By: BuickGN
Originally Posted By: Gary Allan
Steve ..take any passenger car chassis ..and load it up to the power output:load ratio of your former big rig fully loaded ..and run it 60% of the time that way. It will take some conversions and some allowances ..but I don't think you would be using 0w-20 oil to eek out a few more mpg's. You would be factored to make the thing last in that type of service.



So going by this logic, are you admitting that some extra wear occurs in your automobile when run hard on a 20wt over a 40wt?


Not at all. I was pointing out why some engine use a 40 weight...and sensibly so. Steve just couldn't get wrapped around the differences in service duty and designs.

If you COULD scale down an OTR application to equivalent passenger car usage ..and operated it in the same manner, you would probably not be able to use a 20 weight and have the same scaled down time ..overhaul rate. You would probably require a 40 weight.

I'd never suggest that you use a 20 weight with your power output capability. Even if you don't see it too often. With all things considered, there are sensible limits in either peak output to typical output (as in commonly sustained).

So take Steve's OTR truck ..shrink it down 1/20th scale and eliminate 95% of the load ..design the engine from the ground up ..and make it a gas engine so that soot control and all the neat things that come in 15w-40 would be out of the picture ..

..and do you think that a 40 weight would be required? Would a 30 weight work? Why not a 50 weight? Doug surely is missing BIG savings by not using 50 or 60 weights if they reduce wear.

Or is 40 some "magic number" in the universe for viscosity? That is, there's no reason scientically explainable ..it's just one of those wonders of the universe that man has never challenged and proven false.

I don't know how much more fair and balanced I can be here. There surely are applications for heavier oils. But anyone who just says "heavier is bettah" without factoring and qualifying it ..well they obviously aren't looking beyond their own personal bias.

 

[SuperBusa]

Originally Posted By: ekpolk
Allright, let's try to get this back to some form of specific discussion, and not the sweeping generalities that have been filling up the last few pages.

So, let's rephrase the question. What do you all think is the "optimal" kinematic vis for a specific engine in a specific usage.


The one called out by the engine manufacturer for the conditions it was designed to operate in. ... now that was pretty easy, huh?

 

[ekpolk]

Originally Posted By: SuperBusa
Originally Posted By: ekpolk
Allright, let's try to get this back to some form of specific discussion, and not the sweeping generalities that have been filling up the last few pages.

So, let's rephrase the question. What do you all think is the "optimal" kinematic vis for a specific engine in a specific usage.


The one called out by the engine manufacturer for the conditions it was designed to operate in. ... now that was pretty easy, huh?

{laughing Jabba the Hut laughter} Waaaay too easy, I'm afraid. In fact, we may just have to ban you altogether -- we can't have dangerous ideas like this taking hold here! Why if everyone bought into such ideas, there wouldn't be anything left to debate!!!

 

[XS650]

I would be more interested in what the engine designers used in their own cars than what the "manufacturer" recommends after dumbing the options down for the general public, to make it easy for dealer stocking and to satisfy CAFE.

 

[SuperBusa]

Originally Posted By: ekpolk
Why if everyone bought into such ideas, there wouldn't be anything left to debate!!!

... yeah, there wound't be any fun times with all this "debating" going on so I guess it's all good.

 

[BuickGN]

Originally Posted By: Gary Allan
Originally Posted By: BuickGN
Originally Posted By: Gary Allan
Steve ..take any passenger car chassis ..and load it up to the power output:load ratio of your former big rig fully loaded ..and run it 60% of the time that way. It will take some conversions and some allowances ..but I don't think you would be using 0w-20 oil to eek out a few more mpg's. You would be factored to make the thing last in that type of service.



So going by this logic, are you admitting that some extra wear occurs in your automobile when run hard on a 20wt over a 40wt?


Not at all. I was pointing out why some engine use a 40 weight...and sensibly so. Steve just couldn't get wrapped around the differences in service duty and designs.

If you COULD scale down an OTR application to equivalent passenger car usage ..and operated it in the same manner, you would probably not be able to use a 20 weight and have the same scaled down time ..overhaul rate. You would probably require a 40 weight.

I'd never suggest that you use a 20 weight with your power output capability. Even if you don't see it too often. With all things considered, there are sensible limits in either peak output to typical output (as in commonly sustained).

So take Steve's OTR truck ..shrink it down 1/20th scale and eliminate 95% of the load ..design the engine from the ground up ..and make it a gas engine so that soot control and all the neat things that come in 15w-40 would be out of the picture ..

..and do you think that a 40 weight would be required? Would a 30 weight work? Why not a 50 weight? Doug surely is missing BIG savings by not using 50 or 60 weights if they reduce wear.

Or is 40 some "magic number" in the universe for viscosity? That is, there's no reason scientically explainable ..it's just one of those wonders of the universe that man has never challenged and proven false.

I don't know how much more fair and balanced I can be here. There surely are applications for heavier oils. But anyone who just says "heavier is bettah" without factoring and qualifying it ..well they obviously aren't looking beyond their own personal bias.


I guess what I'm looking for is an admission that higher power outputs regardless of temperature require higher viscosities to keep things separated.

 

[Gary Allan]

I won't argue with that ..but the two usually go hand in hand. We could also be talking higher spring rates ..which are going to be higher spring rates even at ZERO output. Lots of things to consider.

What would be debatable at that point is what's considered higher power outputs. 60hp/liter is pretty much generic standard and seems to be some limit to NA applications without some fancy mojo (vvt, etc.).

 

[ekpolk]

Originally Posted By: SuperBusa
. . . dude, it's an example to get the point across. Did I say anyone suggested they run thin oil in a dragster?! ... you're more of a drama queen than ol' Gary is!

Oh no! No, no, no! You made a classic ad absurdum argument argument, and I busted you on it. No free wriggling away here!

Here's a tip from a 15+ year criminal defense trial lawyer -- never over-argue a point. "Under-argument" wins at least 10x more often than over-argument. EDIT: Kinda like how thinner oils do better about 10x of the time, compared to thicker ones!

You over-argued. And I busted ya for it. Remember, in space (and court, and on BITOG), nobody can hear you scream. . .

 

[FZ1]

Friday night fight nite, and thin wins!

 

[AEHaas]

Dragsters start out with a 70 grade oil but end up with almost straight fuel as oil by the end of the strip. This is why they start out so thick.

Thin oil, a 20 grade is best for all around use:

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1543003#Post1543003

aehaas

 

[ekpolk]

Originally Posted By: BuickGN
. . .

I guess what I'm looking for is an admission that higher power outputs regardless of temperature require higher viscosities to keep things separated.


And I would give you that, except for the fact that the designs of the engine internals are not a constant. I envision in the distant future that we will see machines such as personal transport devices (cars) with motors and engines with air-lubricated bearings made with very, very close clearances. And beyond that, perhaps electromagnetic bearings with no physical substance between the surfaces keeping them apart. Obviously, we still have a way to go...

But I'm getting way ahead of things. I can not, in good faith, give you the admission you seek, at least not all of it. With a bunch of qualifiers, sure. The ones that leap off the paper, so to speak, would be things like area of bearing surface, normal operating temps (oil and coolant), normal rpm range, etc. All things being equal, perhaps.

Now, I want YOU to admit that for apps in which there is virtually zero chance of EVER seeing the extreme conditions which you cite, lower vis lubes are perfectly OK.

Whether or not we ever reach agreement on this, have a safe weekend, and be sure to come back to be flogged by me again!

 

[ekpolk]

Originally Posted By: AEHaas
Dragsters start out with a 70 grade oil but end up with almost straight fuel as oil by the end of the strip. This is why they start out so thick.

Thin oil, a 20 grade is best for all around use:

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1543003#Post1543003

aehaas


Dr, you are a heretic!!! At least to the thick guys. Thank you for jumping in here.

That said, you'll be needing to get back into defilade, ASAP. "Defilade" is an almost purely military term. In essence, it means keeping yourself, using whatever surroundings are available, blocked from a direct shot from the enemy, including their snipers.

One of my very best friends growing up is now a neurosurgeon up in Maine. The only time I can remember stumping him is with the term "defilade".

Make my day and tell me that I got you too, doc!!! But hey, either way, this is a win-win. If you actually knew of "defilade" before this thread, my cover's off to you. If not, find defilade quickly, 'cuz the thick guys will shortly be firing upon you from all directions.

 

[AEHaas]

'New word for me, thanks.

 

[ekpolk]

Originally Posted By: AEHaas
'New word for me, thanks.


Dr. you are my hero! For at least a short period of time, you have "made my day"!!! Hey, I'm neither Clint, nor Dirty Harry, but for a brief interval ... well, you get the idea!

Anyway, if you haven't googled it yet, "defilade" is where you want to be if somebody is shooting at you, and the kids who are relying upon you to get them home in one piece...

And just in case there's any hint of "wrong" tone in my post, I must say, as a 29-year Marine, those of you who earned an M.D. or a D.O. are every bit as much heros as that 18-year-old Marine, Soldier, Sailor, or Airman who has the 'nads to climb out of a fighting hole and pursue Osama and his minions.