2021 Odyssey oil spec

[ZeeOSix]

Show of hands ...
How many "thickies" think oil viscosity will overcome design shortcomings and manufacturing flaws such as:
- Chrysler MDS
- Honda VCM
- Kia Theta 2 cranks
- Toyota 3.4L TT machining debris
- Saturn SL2 engines with no oil drain back holes in the rings
- etc ...

Going up a viscosity grade (or sometimes two) isn't about "fixing" design or materials flaws with an engine. It's about giving the moving parts better wear protection headroom and reducing wear over the long run, and to add more protection if the driving conditions become a bit more severe. Ford went up a grade on their Coyote V8 in 2021 from 5W-20 to 5W-30 ... and it wasn't to get more CAFE credits. And no parts clearances have changed in the Coyote since it first came out in 2011.

 

[ZeeOSix]

GM made an engine that doesn't work well on 0w20. Their public statements suggest they think it will work on 0w40. Yes, we're skeptical, but it's quite clear that GM seems to think the thicker oil is sufficient to remedy whatever condition made the 0w20 insufficient.

If GM claims that 0W-40 actually works better and fixes the issue, than the 0W-20 wasn't producing enough film thickness between the moving parts. For example, if the force supporting area between the parts was a bit too small, like journal bearings not designed quite wide enough for the max loads with 5W-20, then a higher viscosity would help due to more film thickness (MOFT).

 

[ChrisD46]

This was from 2005 from an old Toyota R&D article I had posted 20 years ago:

"Lowering the viscosity of engine oil is effective in reducing the fluid friction. However, it decreases the oil film thickness, and causes the increase in the wear of engine parts. Through the engine wear tests using an radioisotope tracer technique, it was clarified that an HTHS viscosity of 2.6 mPa¥s was the lower limit to prevent the increasing wear. It was also found that the influence of the lowering viscosity on the wear of piston rings was larger than that on the wear of the cams and connecting rod bearings.

Addition of friction modifiers is effective in reducing the friction under boundary lubricating conditions. MoDTC was determined as an excellent friction modifier, after evaluating its effects on the friction of valve train and on the fuel consumption of engine. The effect of MoDTC on the friction reduction was considered to be caused by both of the MoS2 film formed and the rubbing surface smoothness that decreased the metal contact.

From the results of these investigations, it was concluded that the points of designing low friction engine oil were lowering the HTHS viscosity to 2.6 mPa¥s and the addition of MoDTC. Based on this guideline, a low friction engine oil has been developed, and it contributes to the improving fuel consumption of automobiles."

"It is also important to note that, contrary to what many take for granted, higher viscosity in and of itself does not translate into better engine protection. Extensive testing has shown the opposite to be in fact true. As long as a lower-viscosity oil is formulated to resist evaporation and provide high film strength, this lighter oil will actually deliver more complete protection to the engine parts, since its more rapid circulation delivers both better lubrication per se, and far better cooling characteristics…a critical advantage, given that oil flow furnishes up to 30%"

Good comments , curious what may be considered too high a viscosity / HTHS oil for a modern engine say with VVT ? Next , blending an oil for engines is a matter of efficiency versus longevity I suppose … As an example , perhaps running 3 qrts. of M1 5W30 ESP + 2 qrts. of 0W20 ESP X2 oil covers all bases for efficiency vs longevity of engines (lol !)

 

[Mainia]

I wouldn't call it "mist", it's the spray off the rod bearings.

Add underside piston crown oil squirters into the mix.

 

[ZeeOSix]

^^^
"It is also important to note that, contrary to what many take for granted, higher viscosity in and of itself does not translate into better engine protection. Extensive testing has shown the opposite to be in fact true. As long as a lower-viscosity oil is formulated to resist evaporation and provide high film strength, this lighter oil will actually deliver more complete protection to the engine parts, since its more rapid circulation delivers both better lubrication per se, and far better cooling characteristics…a critical advantage, given that oil flow furnishes up to 30%"

If all other factors are constant, many wear studies have shown that more HTHS viscosity increases the film thickness (MOFT) between moving parts, which translates to more part separation and therefore less rubbing and wear. Sure, the "film strength" of the oil is important too (ie, the AF/AW additives that provides the wear protecting tribofilm), but viscosity is the main wear mitigation factor. The goal is to keep moving parts separated as much as possible, then rely on the AF/AW tribofilm to take up what film thickness can't.

This Machine Lubrication article has been posted quite a few times, and it distinguishes the difference between film thickness from viscosity and film strength from AF/AW additives.

https://www.machinerylubrication.com/Read/30835/lubricant-film-strength

Also, the temperature increase inside the journal bearings with a thicker oil is pretty small, and not enough to really matter. High performance engines spec thicker oil for track use, and if the slight increase in the bearing film was too much then there wouldn't be any advantage to running a thicker oil on the track. But the temperature rise is minor, so the thicker oil even if running hotter is still providing more MOFT than a thinner oil would in track use conditions.

 

[BornSlippy]

^^^
"It is also important to note that, contrary to what many take for granted, higher viscosity in and of itself does not translate into better engine protection. Extensive testing has shown the opposite to be in fact true. As long as a lower-viscosity oil is formulated to resist evaporation and provide high film strength, this lighter oil will actually deliver more complete protection to the engine parts, since its more rapid circulation delivers both better lubrication per se, and far better cooling characteristics…a critical advantage, given that oil flow furnishes up to 30%"

If all other factors are constant, many wear studies have shown that more HTHS viscosity increases the film thickness (MOFT) between moving parts, which translates to more part separation and therefore less rubbing and wear. Sure, the "film strength" of the oil is important too (ie, the AF/AW additives that provides the wear protecting tribofilm), but viscosity is the main wear mitigation factor. The goal is to keep moving parts separated as much as possible, then rely on the AF/AW tribofilm to take up what film thickness can't.

This Machine Lubrication article has been posted quite a few times, and it distinguishes the difference between film thickness from viscosity and film strength from AF/AW additives.

https://www.machinerylubrication.com/Read/30835/lubricant-film-strength

Also, the temperature increase inside the journal bearings with a thicker oil is pretty small, and not enough to really matter. High performance engines spec thicker oil for track use, and if the slight increase in the bearing film was too much then there wouldn't be any advantage to running a thicker oil on the track. But the temperature rise is minor, so the thicker oil even if running hotter is still providing more MOFT than a thinner oil would in track use conditions.

If off the shelf mainstream lubes were formulated without lowest price being a factor, then 0W-20 would work great in most of todays engines.

Take something like @OVERKILL custom blended HPL 0W-20 Supercar and you have a shear stable oil that runs very clean and has an abundance of anti-wear and friction modifying additives.

In Afton's GF-7 guide, they allude to the quality of GF-6 lubes of today not being high quality enough. Of course everything is blended to a price point. A quality lube such as HPL is two to three times the price of an off the shelf lube such as M1 EP, Castrol EDGE EP or Pennzoil Ultra Platinum.

So what's a guy to do? Pony up the cash and buy a better lube is one option. Another option is to go for a thicker viscosity and change it more frequently.

 

[Hohn]

Good comments , curious what may be considered too high a viscosity / HTHS oil for a modern engine say with VVT ? Next , blending an oil for engines is a matter of efficiency versus longevity I suppose … As an example , perhaps running 3 qrts. of M1 5W30 ESP + 2 qrts. of 0W20 ESP X2 oil covers all bases for efficiency vs longevity of engines (lol !)

It’s much, much higher than any grade we’re talking about here.

 

[ARB1977]

I’ve ran both 0W and 5W30 Amsoil in the Pilot.

 

[OVERKILL]

I tried it once, a long time ago on a 2015 RAM 1500, no thermostat, no shutters, and once it got up to temperature it wouldn't go bellow 185F on the highway. This was a long time ago, I no longer have it.

Interesting, when the Thermostat stuck open on our Expedition it wouldn't come off "cold" on the gauge, which was probably around 100F? The rad hoses would get only slightly warm, you could easily, and comfortably, keep your hand on them.

 

[OVERKILL]

Still has some life left. Stellantis is resuming production of the HEMI.

That's excellent, it's a great engine. Simple is good. It's a pig on fuel, but there's a role for it still IMHO.

 

[OVERKILL]

Add underside piston crown oil squirters into the mix.

Where equipped, sure. Traditionally, they were very uncommon.

 

[Lawnman23]

Where equipped, sure. Traditionally, they were very uncommon.

Seems to have become more common on non-performance engines. The GM 3.6 LFX that came out in 2012 has them I discovered.

Also noticed them more and more on tear downs on https://m.youtube.com/@I_Do_Cars

 

[OVERKILL]

Seems to have become more common on non-performance engines. The GM 3.6 LFX that came out in 2012 has them I discovered.

Also noticed them more and more on tear downs on https://m.youtube.com/@I_Do_Cars

Yes, as power density has increased and more engines have forced induction, we are seeing them used more frequently. My 6.4L has them, my 5.7L doesn't IIRC.

 

[Bill7]

Show of hands ...
How many "thickies" think oil viscosity will overcome design shortcomings and manufacturing flaws such as:
- Chrysler MDS
- Honda VCM
- Kia Theta 2 cranks
- Toyota 3.4L TT machining debris
- Saturn SL2 engines with no oil drain back holes in the rings
- etc ...

It's a fact that oil gets thinner as it gets hotter.
If you have an engine that has hotspots (like the gen 1 Honda VCM engines that cook the oil on the cylinder heads),
a thicker oil with withstand the extreme heat better than a thin oil.

Note: GM engineers wanted to change the oil to prevent the manufacturing flaw from causing issues.
They could have changed their recommendation from 0W-20 to 0W-16 or 0W-8, but they chose 0W-40.
GM engineers know a lot about engines, and we can learn from their new recommendation.

 

[Klutch9]

Yes, as power density has increased and more engines have forced induction, we are seeing them used more frequently. My 6.4L has them, my 5.7L doesn't IIRC.

Both our vehicles have them (2016 Explorer 2.3 and 2024 Carnival).

 

[cammyfive79]

Indeed. It's a stone age port injected engine.

Years ago when DI was becoming mainstream and every magazine article was touting it's increased power etc I was a little frustrated that my previous TSX wasn't DI let alone forced injection.....now I'm all but ecstatic that it is not.

 

[factorytuned2012]

The insane 0w-20 to 0w-40 GM jump got me thinking.. about my personal 21’ Honda odyssey. Normal US spec is 0w-20. So I dug around thinking, huh what’s it in…Mexico…

If I hear another word about “tighter tolerances” lmao

View attachment 277667

View attachment 277668

Looks like you could use whatever that chart says. Go ahead with it.

 

[OVERKILL]

Years ago when DI was becoming mainstream and every magazine article was touting it's increased power etc I was a little frustrated that my previous TSX wasn't DI let alone forced injection.....now I'm all but ecstatic that it is not.

Yep, that's one of the reasons my parents ended up with a HEMI-powered GC-L. It has a VERY conventional powertrain, probably the best transmission currently available, and no auto start stop.

 

[Elmo Howe]

Seems to have become more common on non-performance engines. The GM 3.6 LFX that came out in 2012 has them I discovered.

Also noticed them more and more on tear downs on https://m.youtube.com/@I_Do_Cars

The Toyota " Global platform" 2.0 liter and 2.5 liter engines , hybrid and non hybrid, have the piston oil squirters also.

 

[K24Z7&M20AFXS]

I'm sorry for bringing this up, it's not my intention to derail this thread. I'll keep it short: when you remove the grille shutters and either install like a 160F or 180F thermostat, or no thermostat at all, you will notice that you can't get the coolant cooler than around 185F. That's the cooling system wall, or limitation. Every engine/cooling system has a wall like this. It's also called "cooling capacity". And for every engine it's different. That's what I was referring to.

I haven't experimented with running no thermostat, 180F = 82C, the coolant temp is locked to 85 so a few degrees higher than the thermostat rating. I don't know how cool the engine would get with no thermostat at all, could be this is as low as it goes.

They have high temps thermostats because a higher temperature thermostat improves thermal efficiency among other things. A "hotter" engines can absorb less heat then a colder engine. Better run a colder thermostat if you plan to tune the engine however as there are gains to be found there from a performance point of view.

Running no thermostat is a bad idea. The engine, ultimately won't really run colder but will take one hell of a time to heat up (if it ever heats up.) and will wear out faster due to high tolerances (when cold) and running pig rich. You can also throw a CEL if the PCM wonders what is going on.

If GM claims that 0W-40 actually works better and fixes the issue, than the 0W-20 wasn't producing enough film thickness between the moving parts. For example, if the force supporting area between the parts was a bit too small, like journal bearings not designed quite wide enough for the max loads with 5W-20, then a higher viscosity would help due to more film thickness (MOFT).

I don't think the problem is the engine in that case. I thing it's CAFE. Those engines apparently weren't "problematic" before they mandated 0w20 in 2021. Maybe a failed example here and there like everybody else but not at pandemic level like we see now. My guess? With 0w40, you will not hear anything about failed bearings in those 6.2 like we hear now. It's only a guess but i think it's a good one.

Interesting, when the Thermostat stuck open on our Expedition it wouldn't come off "cold" on the gauge, which was probably around 100F? The rad hoses would get only slightly warm, you could easily, and comfortably, keep your hand on them.

Yep. Normally, a stuck open thermostat won't allow the engine to reach operating temperature. Depending on the age/generation of PCM and brand, it might not gen on closed loop, might run pig rich and will wear out the engine faster due to tolerances in the engine not "closing out". Among other things...

Where equipped, sure. Traditionally, they were very uncommon.

Nowadays, i think the engines that don't have oil squirters are uncommon. Lol. Both my Priuses have them and i think that my K24 might have some too. Just not sure about the K24 as it's from a 2012 Civic Si..

Years ago when DI was becoming mainstream and every magazine article was touting it's increased power etc I was a little frustrated that my previous TSX wasn't DI let alone forced injection.....now I'm all but ecstatic that it is not.

I'm glad to have D4-S in the 2024 Prime from an efficiency/cleanliness of valves point of view. I'm also glad that the K24 is port injected as finding performance injectors sure is easier on Port Injection than Direct Injection.