We finally got some... 0W-8.

[OVERKILL]

Toyota, IF….., more data needed.

Jesus dude, what additional data is needed? The same engine, in Australia, which has no CAFE, is provided with a range of acceptable oil grades all the way from 0W-16 to 10W-30, while in North America, with CAFE, is provided with a single grade of 0W-8 (previously 0W-16), because that's what it was qualified for CAFE on.

What do you think is a more reasonable premise here:
1. Toyota is secretly loosening up the bearing clearances and manufacturing a different version of the engine for the tiny Australian domestic market, while not changing the engine code, and yet somehow still permitting 0W-16.

OR

2. Toyota, unconstrained by CAFE, spec's a range of grades in Australia, including 0W-16, because they are all acceptable for the engine.

 

[Fair enough]

It absolutely matters that CAFE is the reason. If you can't spec other viscosities, you only get the one the vehicle was qualified on, it's a pretty simple concept.

But they DO put thicker oils in the manual in markets that don't have CAFE, like Australia. Just like @ZeeOSix posted, here are the oil spec pages for the 2023 Corolla from Australia:
View attachment 250995.
View attachment 250996

Same manual (note the same engine code) for North America:
View attachment 250997
View attachment 250998


So the same engine spec's everything from 0W-8 (CAFE land!) to 5W-30/10W-30 (Australia).

It’s just about engine oil. I myself was thinking to use a thicker grade oil to reduce start up rattle on one car that specs thinner. You and 06 are pretty fair. Actually discuss without judging so much. A little bit. In Australia is pretty good data. But the USA is a lot colder. If they reduced the clearances like the article I posted states, maybe it is still fine to use thicker in Australia using the same engine because it’s warmer. They still say 0 16 preferred in Australia, with no CAFE. What’s the explanation for that? Maybe Australia words their version of CAFE differently, if they have one. The underlying point is did Toyota reduce the bearing clearances to use 0 8 or 16. If they did then using these should be fine, referencing my article above. Not just fine, but preferred in their words.

 

[kschachn]

Jesus dude, what additional data is needed? The same engine, in Australia, which has no CAFE, is provided with a range of acceptable oil grades all the way from 0W-16 to 10W-30, while in North America, with CAFE, is provided with a single grade of 0W-8 (previously 0W-16), because that's what it was qualified for CAFE on.

What do you think is a more reasonable premise here:
1. Toyota is secretly loosening up the bearing clearances and manufacturing a different version of the engine for the tiny Australian domestic market, while not changing the engine code, and yet somehow still permitting 0W-16.

OR

2. Toyota, unconstrained by CAFE, spec's a range of grades in Australia, including 0W-16, because they are all acceptable for the engine.

Plus I have posted multiple times the EPA letters automakers receive regarding the recommendations they are permitted to make in their owner’s manuals after fuel economy testing. It is bordering on bizarre to make any sort of technical or mechanical argument in light of the regulatory requirements, much less basic physics.

But this is what you get when someone is likely on ignore

 

[kschachn]

Never mind. It won’t make a bit of difference here. The Twilight Zone is fully into play.

Multiple user names over multiple years and still making the same technically baseless comments. Why expect a change now?

 

[Elkins45]

Toyota, IF….., more data needed.

My 2016 Mazda6 (Skyactiv) manual says use 0w-20 if you’re in the USA but use 5w-30 if you’re in Mexico. No distinction is made between temperature variations in different geographic regions within the two countries.

That’s CAFE all the way.

 

[OVERKILL]

It’s just about engine oil. I myself was thinking to use a thicker grade oil to reduce start up rattle on one car that specs thinner. You and 06 are pretty fair. Actually discuss without judging so much. A little bit. In Australia is pretty good data. But the USA is a lot colder.

I mean, Texas and Arizona are definitely not a lot colder. This is the issue with CAFE, it prevents them from spec'ing different grades for different anticipated ambient conditions, which means, if say 0W-16 was more appropriate than 0W-8 in Arizona, they can't say that.

If they reduced the clearances like the article I posted states, maybe it is still fine to use thicker in Australia using the same engine because it’s warmer. They still say 0 16 preferred in Australia, with no CAFE. What’s the explanation for that?

Your article isn't specific to Toyota, it's a general "rule of thumb", which is how to we got into the conversation about clearances, generally, being pretty consistent from most marques across the board and the design change we've seen from marques pushing below the 2.6cP HTHS threshold being bearing width.

0W-16 is the "preferred" grade in Australia because that was likely the grade the engine was developed with (wider bearings). They've revised the spec to 0W-8 for North America (from 0W-16) because it has proven to increase fuel economy (better for CAFE) while still providing adequate wear protection.

Maybe Australia words their version of CAFE differently, if they have one. The underlying point is did Toyota reduce the bearing clearances to use 0 8 or 16. If they did then using these should be fine, referencing my article above. Not just fine, but preferred in their words.

Australia doesn't have CAFE, so they can give a range, North America does, so they can't. That's why the same engine can spec a range of acceptable grades from 0W-16 all the way to 10W-30 in Australia, while the manual is restricted to stating the CAFE qualified grade (0W-8) in North America.

 

[tolian21]

My Acura RDX has the same, in US its 0w-20 in Texas, Florida and Arizona, but few miles across the border in mexico 5w-30 is in the manual. So cold vs hot climate is a false argument.

 

[Glenda W.]

Toyota, IF….., more data needed.

 

[ZeeOSix]

The underlying point is did Toyota reduce the bearing clearances to use 0 8 or 16. If they did then using these should be fine, referencing my article above. Not just fine, but preferred in their words.

How tight do you think journal bearings can go? I mean do you think a 0.0006 inch clearance can go even smaller? I certainly don't because there is a point where too tight will over heat them regardless of what oil viscosity is used. I highly doubt the journal bearing clearance in engines spec'd for 0W-8 or 0W-16 are any tighter than 0.0006 in which I showed with the XSR900 example that can run 20W-50. Go find the service manual somewhere and show what the actual bearing clearance range is on these engines. As mentioned by @OVERKILL they are wider, not necessarily tighter.

They use the word "preferred" (not "required") in the OM because of two reasons: 1) Mainly CAFE in the USA, and 2) Because they want people to use the oil the vehicle qualified for to obtain the MPG claims regardless of CAFE to make the window sticker look as attractive as possible to potential buyers who focus on fuel economy. The bearings were not "designed" for any specific oil viscosity, they were designed to work on a range of oil viscosity, just as the OMs show for the same engine in different countries.

 

[ZeeOSix]

It’s just about engine oil. I myself was thinking to use a thicker grade oil to reduce start up rattle on one car that specs thinner.

With a higher W grade?

 

[cryptolyme]

We at the Advance Auto finally got our hands on some 0w-8 oil. We don't stock this stuff, and most stores won't. We special ordered it for one of our commercial accounts. In fact, we still don't have any 0W-16 out on the shelves yet.

Anyway I noticed no API certification on it. It does say Made in the USA on the bottle though. Looks to a Mobil bottle?
View attachment 248240View attachment 248241

only the best for my high hp engines. thinner the better!

 

[cryptolyme]

It’s just about engine oil. I myself was thinking to use a thicker grade oil to reduce start up rattle on one car that specs thinner. You and 06 are pretty fair. Actually discuss without judging so much. A little bit. In Australia is pretty good data. But the USA is a lot colder. If they reduced the clearances like the article I posted states, maybe it is still fine to use thicker in Australia using the same engine because it’s warmer. They still say 0 16 preferred in Australia, with no CAFE. What’s the explanation for that? Maybe Australia words their version of CAFE differently, if they have one. The underlying point is did Toyota reduce the bearing clearances to use 0 8 or 16. If they did then using these should be fine, referencing my article above. Not just fine, but preferred in their words.

i think they use wider bearings but with the same clearances to allow for lower viscosity while still allowing for thicker oils to be used. kind of frustrating they spec all sorts of different oil weights. i just want what's best for my engine. i don't care about efficiency.

 

[ZeeOSix]

kind of frustrating they spec all sorts of different oil weights. i just want what's best for my engine. i don't care about efficiency.

Then go up a KV100 grade from the CAFE driven "recommended" viscosity. It's simple ... just pour it in.

 

[Fair enough]

How tight do you think journal bearings can go? I mean do you think a 0.0006 inch clearance can go even smaller? I certainly don't because there is a point where too tight will over heat them regardless of what oil viscosity is used. I highly doubt the journal bearing clearance in engines spec'd for 0W-8 or 0W-16 are any tighter than 0.0006 in which I showed with the XSR900 example that can run 20W-50. Go find the service manual somewhere and show what the actual bearing clearance range is on these engines. As mentioned by @OVERKILL they are wider, not necessarily tighter.

They use the word "preferred" (not "required") in the OM because of two reasons: 1) Mainly CAFE in the USA, and 2) Because they want people to use the oil the vehicle qualified for to obtain the MPG claims regardless of CAFE to make the window sticker look as attractive as possible to potential buyers who focus on fuel economy. The bearings were not "designed" for any specific oil viscosity, they were designed to work on a range of oil viscosity, just as the OMs show for the same engine in different countries.

.0001/4” or 2.54 microns / 4 in the early twentieth century, or earlier. I could say more but you pick it apart. Then they would say 25 millionths. Yes designed is an ok word to use.

Like where is the regulation about owners manuals? If it is there, fine. But is it there?

 

[kschachn]

Like where is the regulation about owners manuals? If it is there, fine. But is it there?

I already said need more data twice, and I am not about to look for it. I end at need more data. That’s why I didn’t go look for it.

Like, another casualty of apparently having someone on ignore.

 

[ZeeOSix]

.0001/4” or 2.54 microns / 4 in the early twentieth century, or earlier. I could say more but you pick it apart. Yes designed is an ok word to use.

You think journal bearings in an ICE are going survive with a clearance of 0.0001 inch (2.54 microns) divided by 4 = 0.000025 inch? Even a clearance of 0.0001 inch is too tight. What bearings are you talking about, and you have a source to back up that claim?

More like bearings glowing orange before they seize with 0.000025 inch clearance.

Like where is the regulation about owners manuals? If it is there, fine. But is it there?

What regulation?

 

[PandaBear]

My 2016 Mazda6 (Skyactiv) manual says use 0w-20 if you’re in the USA but use 5w-30 if you’re in Mexico. No distinction is made between temperature variations in different geographic regions within the two countries.

That’s CAFE all the way.

There's no Alaska in Mexico.

 

[wemay]

Do i gotta chase my tail again?!

 

[Fair enough]

You think journal bearings in an ICE are going survive with a clearance of 0.0001 inch (2.54 microns) divided by 4 = 0.000025 inch? Even a clearance of 0.0001 inch is too tight. What bearings are you talking about, and you have a source to back up that claim?

More like bearings glowing orange before they seize with 0.000025 inch clearance.

View attachment 251062


What regulation?

You get journal answer based on question.
Regulation where they are forbidden to add temp charts to the owners manual for oil.
Maybe it’s a thing, I just ask.

 

[ZeeOSix]

You get journal answer based on question.

You should probably learn more about journal bearings before getting too deep into the technical discussions about how they work.

Regulation where they are forbidden to add temp charts to the owners manual for oil.
Maybe it’s a thing, I just ask.

It was already mentioned in this thread. In order to get CAFE credits, the OM needs to recommend the oil viscosity the vehicle was EPA fuel mileage tested with. They can't test with 0W-8 to get the best possible fuel mileage rating, then recommend 10W-40 in the OM. The oil that's "recommended" in the OM, and shown on the oil cap is the viscosity the engine was EPA fuel mileage tested with.

CAFE/EPA regulations say it needs to be shown on the oil fill cap and in the OM. The OM needs to constantly "push" the "recommended" viscosity (the viscosity it was EPA tested with). Toyota OMs say you can use 0W-16 if 0W-8 isn't available, but then says it needs to be changed back to 0W-8 at the next oil change. That's why they say that - to push the recommend viscosity ... it's not because 0W-16 is bad for the engine. And the Toyota OM also says that thicker oil will give better protection in harsh use conditions - why would they say that if it wasn't true. That's their way of getting around CAFE to some extent and saying thicker oil is OK to use.