Why does Toyota recommend 0W-20?

[PimTac]

"And to answer that directly, the primary concern is fuel economy. As Honda puts it, wear with XW-20 and thinner oils is "acceptable", not optimal. I have no problem with "acceptable", that doesn't mean it will significantly impact the engine longevity in and of itself."





This has been a million dollar question here and may not ever be answered fully. Acceptable wear depends on so many variables in the real world. In a lab setting it might be clearer due to controls. If a engine ran 300,000 miles on 5w30 and 280,000 miles on 0w20, that might be considered acceptable. Who would know?

My opinion is that this is closer to the truth than the thought that the manufacturer only worries about the warranty period. If engines were wearing out long before 100k we would know it. That is not the case.

 

[Hall]

Originally Posted by billt460
I'm having trouble finding 0W-16 both here....

I can't say I specifically look for it but I've never seen it on store shelves between Walmart, Autozone, or O'Reilly (the stores I've been to most recently).

Looking at Walmart's website, they don't even have 0W-16 in their filter to select. Same with Autozone's website...

 

[blupupher]

I am with others in thinking the 0w-20 is due to Toyotas change to 10,000 mile intervals, and 0w-20 almost guarantees synthetic oil.
A synthetic 5w-20 will make no notable difference and could go the full recommended Toyota interval.
Then again, a SN+ "conventional" oil probably could do it as well.

I switch between 0w-20 and 5w-20 in my Scion (a 2AZ-FE Toyota motor) that the owners manual says "SAE 5W-20 or 0W-20 engine oil may be used. However, SAE 0W-20 is the best choice for good fuel economy and good starting in cold weather".
My current plan is to use up my 20 qts of 0w-20 first, then move to the 15 qts of 5w-20 (if I have any left, it is what I use in my truck also), then 5w-30.

 

[Mad_Hatter]

Originally Posted by PimTac

This has been a million dollar question here and may not ever be answered fully. Acceptable wear depends on so many variables in the real world. In a lab setting it might be clearer due to controls. If a engine ran 300,000 miles on 5w30 and 280,000 miles on 0w20, that might be considered acceptable. Who would know?

My opinion is that this is closer to the truth than the thought that the manufacturer only worries about the warranty period. If engines were wearing out long before 100k we would know it. That is not the case.

Sure there might not be a dearth of failures at 100k but how many of those engines continue to use 0w20 100k miles later? Why not run a slightly thicker lube to begin with?

 

[PimTac]

Originally Posted by Mad_Hatter
Originally Posted by PimTac

This has been a million dollar question here and may not ever be answered fully. Acceptable wear depends on so many variables in the real world. In a lab setting it might be clearer due to controls. If a engine ran 300,000 miles on 5w30 and 280,000 miles on 0w20, that might be considered acceptable. Who would know?

My opinion is that this is closer to the truth than the thought that the manufacturer only worries about the warranty period. If engines were wearing out long before 100k we would know it. That is not the case.

Sure there might not be a dearth of failures at 100k but how many of those engines continue to use 0w20 100k miles later? Why not run a slightly thicker lube to begin with?




This proves my point. Do you know the numbers?

 

[PowerSurge]

Originally Posted by Richie
my thoughts as well. I know my Tundra in the US calls out to use 0W-20 but the same truck and engine in other countries calls to use 5W-30

Originally Posted by kschachn
Originally Posted by benhen77
I think some of it is gas mileage and start up wear in extreme conditions.

Reduced fuel consumption, yes. Reduced wear, no.



My 5.7 Tundra shows no increased wear metals via Blackstone while using 0w-20 year-round. And I'm in the Hotlanta area.

 

[Silver]

Originally Posted by kschachn
Originally Posted by benhen77
I think some of it is gas mileage and start up wear in extreme conditions.

Reduced fuel consumption, yes. Reduced wear, no.


I'm not saying you're wrong, but most of the world including most folks on this forum I dare say believe a 0W will provide relatively quicker flow at startup over a 5W or 10W, therefore lubricating relatively dry parts quicker, thereby reducing startup wear. Key word relatively, even in warm weather.

I welcome clarification.

 

[aquariuscsm]

I had Valvoline dino 20W50 in my 300ZX on a -4F degree winter morning and she started right up the very second I turned the key. Smooth as glass and no noise.

Imo these uber thin oils are the car manufacturers pushing the envelope to see how thin they can go while pleasing the cafe regulations.

 

[wallyuwl]

Originally Posted by David2431
I see you live in Wisconsin. I live in central Nebraska. Our winters are often similar. Actual outdoor temps can easily fall to -10º and stay there for a week. I've seen -35º, but not as often in more recent times.

We bought a 2014 RAV4 from our daughter's family when the number of kids grew too large for that vehicle. She purchased it new and always used 0W20 as per spec.

When we got the vehicle I wanted to use my stash of 5W20 Phillips Choice syn blend, so after much worry and investigation online I took the plunge and began using it last May. When it's really hot I've been going 50/50 with 5W20 and 5W30.

I see no difference in startup noise, fuel consumption, or oil cleanliness between oil changes. The vehicle uses NO oil between changes with either oil, which are usually every 2,500 miles (we've put 27,000 miles on it in the past 18 months-total mileage is now 102,000.)

This winter I will switch back to 0W20 synthetic (QS) for the coldest months, as the car is stored in a detached, usually unheated garage.

I think much of my worry was for nothing.




Lots of helpful replies, especially the one quoted above.

My stash is 42 quarts of 5W-20. I think it is 10 quarts of M1, 10 of Valvoline Synpower, 10 of Havoline synthetic, and 12 of QSUD. So all synthetic. I also use that grade in my 2018 F150 5.0 Coyote, which is 9 quarts per oil change (but I only change that twice per year). I will use up the stash without worry in the new Highlander, and probably even continue with that grade. I think the thoughts about requiring 0W being Toyota's way of ensuring people are using synthetic makes sense.

 

[kschachn]

Originally Posted by Silver
I'm not saying you're wrong, but most of the world including most folks on this forum I dare say believe a 0W will provide relatively quicker flow at startup over a 5W or 10W, therefore lubricating relatively dry parts quicker, thereby reducing startup wear. Key word relatively, even in warm weather.

I welcome clarification.

You can do your own clarification by plotting out the viscosity vs. temperature at https://www.widman.biz/English/Calculators/Graph.html.

 

[Bryanccfshr]

This is an incorrect Idea/meme, group think . And the repeating of it does not turn it into a fact.
Lower viscosity oils will pump at lower temperature yes. But given any normal ambient temperature. Such as 50 degree Fahrenheit. Both a 0w20 and a 10w30 will pump and reach engine parts at the same time in the same engine. A positive displacement pump moving liquid into a limited volume area channeled into parts will move the same volume of liquid per circuit. So the dirtiest reaches of the oil circuit will get oil at the same time so long as the oil is above its minimum cold crank viscosity rating.
Another misunderstanding is the idea that the parts are dry on startup. No, oil remains on the surfaces of the cams, the cylinder walls and within the bearings (many bearings actually have grooves to retain even more oil for startup.) plus the oil circuit in the engine does not go completely dry when you shut it down. Most filters retain oil downstream of the pump and oil remains in the channels to the galleys within the block up to the journal bearing level were oil drains fem when the engine is shut down.
On a cold star You only need to push oil from the journal bearings to the top circuit of the engine, which would be the cams.
The reason most wear happens during cold start is because the additive package in the oil is not fully activated until it is close to operating temperature., not for a lack of oil.

Now many people will turn to that ESSO video showing 0w30 hdeo beating 15w40 HDEO on cold start. In the Arctic.
And I say of course. The temperatures of the tests were below the minimum cold crank viscosity of that oil. That is why lower viscosity oil is needed in that case. Everything has to be within context.
If you did the same test at a temperate climate say 50-90f then the oil flow would be identical.

So in summary in Texas I get no additional cold start protection from 0w20 than 5w30, 10w30, 0w40 and 15w40*
*unless in the panhandle in winter with record low temps..which I will try like [censored] to avoid because who wants to go up there?


Originally Posted by Silver
Originally Posted by kschachn
Originally Posted by benhen77
I think some of it is gas mileage and start up wear in extreme conditions.

Reduced fuel consumption, yes. Reduced wear, no.


I'm not saying you're wrong, but most of the world including most folks on this forum I dare say believe a 0W will provide relatively quicker flow at startup over a 5W or 10W, therefore lubricating relatively dry parts quicker, thereby reducing startup wear. Key word relatively, even in warm weather.

I welcome clarification.

 

[ZeeOSix]

Originally Posted by Bryanccfshr
But given any normal ambient temperature. Such as 50 degree Fahrenheit. Both a 0w20 and a 10w30 will pump and reach engine parts at the same time in the same engine. A positive displacement pump moving liquid into a limited volume area channeled into parts will move the same volume of liquid per circuit. So the dirtiest reaches of the oil circuit will get oil at the same time so long as the oil is above its minimum cold crank viscosity rating.


True, but what about those areas inside the engine that only get lubrication from oil splashing around (not directly force fed by the oil pump), like cylinder walls, rod small end bearings, cam chains and cam lobes. Those parts will have a residual oil film, but if it's very cold and the oil is very thick it's not going to splash around much until it thins down with heat. Note that this only becomes a real issue in very cold tempetatures.

The difference between 0W-20 and 5W-20 isn't going to show up in terms of cold start-up lubrication until it's well below zero.

I'm wondering if car manufacturers get alittle more CAFE credits if they spec and use 0W-20 vs 5W-20 since 0W-20 might save a miniscule more fuel over many cold starts.

 

[Yah-Tah-Hey]

Originally Posted by PimTac
The number zero just freaks some people out.

You got that right PT. Mention 0W anything and their eyeballs roll around in their head and they start the old "too thin of an oil" speil.

 

[Bryanccfshr]

I have oil squirters that spray the underside of each cylinder with oil, also splashing the cylinder walls.
My timing chain on both my 1gr and 2gr engines has a direct oil squirters onto the chain.
The upper end is part of the pressurized oil circuit, supplying both the VVT as well as to the cam bearings surfaces. The cams are rollerized, reducing the friction even more as the oil pools in this area quickly after reaching the cam bearings. I am certain most engines have similarly robust oil circuits.

Look at pages 20-21 on the below link for a graphic and diagram of the oiling system.

http://www.toyotareference.com/guts/tacoma16_engine.pdf

Originally Posted by ZeeOSix
Originally Posted by Bryanccfshr
But given any normal ambient temperature. Such as 50 degree Fahrenheit. Both a 0w20 and a 10w30 will pump and reach engine parts at the same time in the same engine. A positive displacement pump moving liquid into a limited volume area channeled into parts will move the same volume of liquid per circuit. So the dirtiest reaches of the oil circuit will get oil at the same time so long as the oil is above its minimum cold crank viscosity rating.


True, but what about those areas inside the engine that only get lubrication from oil splashing around (not directly force fed by the oil pump), like cylinder walls, rod small end bearings, cam chains and cam lobes. Those parts will have a residual oil film, but if it's very cold and the oil is very thick it's not going to splash around much until it thins down with heat. Note that this only becomes a real issue in very cold tempetatures.

The difference between 0W-20 and 5W-20 isn't going to show up in terms of cold start-up lubrication until it's well below zero.

I'm wondering if car manufacturers get alittle more CAFE credits if they spec and use 0W-20 vs 5W-20 since 0W-20 might save a miniscule more fuel over many cold starts.

 

[ZeeOSix]

Originally Posted by Bryanccfshr
I have oil squirters that spray the underside of each cylinder with oil, also splashing the cylinder walls.
My timing chain on both my 1gr and 2gr engines has a direct oil squirters onto the chain.
The upper end is part of the pressurized oil circuit, supplying both the VVT as well as to the cam bearings surfaces. The cams are rollerized, reducing the friction even more as the oil pools in this area quickly after reaching the cam bearings. I am certain most engines have similarly robust oil circuits.

Look at pages 20-21 on the below link for a graphic and diagram of the oiling system.

http://www.toyotareference.com/guts/tacoma16_engine.pdf


A lot of engines don't have dedicated piston or cam chain/cam lobe squirters. And almost engines all rely on splash oiling on the rod small end bearing.

Obviously, the oil would have to be super thick in a very cold climate to impact the oiling of parts that are simply oil splashed.

 

[ZeeOSix]

Double post ... deleted.

 

[Bryanccfshr]

It is relevant for this post with "Toyota " in the title. As you can see in the circuit diagram the small end , wrist pin and cams all have pressurized oil passages to them. And these are a decade old design, and Toyota is slow to update things once they get to market.

Originally Posted by ZeeOSix
Originally Posted by Bryanccfshr
I have oil squirters that spray the underside of each cylinder with oil, also splashing the cylinder walls.
My timing chain on both my 1gr and 2gr engines has a direct oil squirters onto the chain.
The upper end is part of the pressurized oil circuit, supplying both the VVT as well as to the cam bearings surfaces. The cams are rollerized, reducing the friction even more as the oil pools in this area quickly after reaching the cam bearings. I am certain most engines have similarly robust oil circuits.

Look at pages 20-21 on the below link for a graphic and diagram of the oiling system.

http://www.toyotareference.com/guts/tacoma16_engine.pdf


A lot of engines don't have dedicated piston or cam chain/cam lobe squirters. And almost engines all rely on splash oiling on the rod small end bearing.

Obviously, the oil would have to be super thick in a very cold climate to impact the oiling of parts that are simply oil splashed.

 

[rummy]

10W-30 oil in my toyota for 5k miles and the report came back excellent. who knows, maybe a 0w could fetch similar results? 🤷â€â™‚ï¸

1ppm/1k miles, on iron. not bad? https://bobistheoilguy.com/forums/attachments/usergals/2017/12/full-74995-16904-img_3826.jpg

i guess i would prob use a 0w oil if i lived in extremely frigid conditions. im still using a 10w for colder months and in summers i run a 15w oil. ohh, the horror! ...… the yota is at 180k now.

also have a 2015 corolla that specs 0w-20 and i run 5w-30 in colder months and 10w-30 in summer. 🤘



Originally Posted by Silver
Originally Posted by kschachn
Originally Posted by benhen77
I think some of it is gas mileage and start up wear in extreme conditions.

Reduced fuel consumption, yes. Reduced wear, no.


I'm not saying you're wrong, but most of the world including most folks on this forum I dare say believe a 0W will provide relatively quicker flow at startup over a 5W or 10W, therefore lubricating relatively dry parts quicker, thereby reducing startup wear. Key word relatively, even in warm weather.

I welcome clarification.

 

[tig1]

Originally Posted by Mad_Hatter
Originally Posted by PimTac

This has been a million dollar question here and may not ever be answered fully. Acceptable wear depends on so many variables in the real world. In a lab setting it might be clearer due to controls. If a engine ran 300,000 miles on 5w30 and 280,000 miles on 0w20, that might be considered acceptable. Who would know?

My opinion is that this is closer to the truth than the thought that the manufacturer only worries about the warranty period. If engines were wearing out long before 100k we would know it. That is not the case.

Sure there might not be a dearth of failures at 100k but how many of those engines continue to use 0w20 100k miles later? Why not run a slightly thicker lube to begin with?

I drive Fords not Toyoto's, but I have put some 502K(my last three cars) on 20 wt M1 oils and 90% of that is with 0-20. Great results.

 

[Lowflyer]

Originally Posted by ZeeOSix
You got that right PT. Mention 0W anything and their eyeballs roll around in their head and they start the old "too thin of an oil" speil.
Silly bellyaching. The first grade are never a problem. 0W or 5W are in regions with cold winter always ok. Second grades and HTHS bloodbaths, as CAFE-nonsense, make all the problems.