0W20 for good protection?

When engineers are not cowering because of CAFE, then they specify oil viscosity that best protects the engine. That's why the same engines used in different countries call out a whole spectrum of oil viscosity based on the ambient temperatures the vehicle is used in.
This! or back to post 21. :p
 
Any modern engine will show ambient temperature and the oil viscosity recommended. Notice that all viscosities are recommended at the same high ambient temperature.
A lot of the modern US models only show one viscosity, and it's typically xW-20, and some call out xW-16. So of courses they would have to show it's applicable for the high temperature range, otherwise they would have to show other higher grades like done in other countries.

Then manufactureres like Toyota will throw in a statement in the OM that higher viscosity will be better for more demanding use conditions, but won't show it in the chart. It's been discussed and shown many times from various Toyota OMs. At least the Toyota engineers give the user some discretion on bumping the viscosiy up if they want to. And they would be following the OM if they did.
 
A lot of the modern US models only show one viscosity, and it's typically xW-20, and some call out xW-16. So of courses they would have to show it's applicable for the high temperature range, otherwise they would have to show other higher grades like done in other countries.

Then manufactureres like Toyota will throw in a statement in the OM that higher viscosity will be better for more demanding use conditions, but won't show it in the chart. It's been discussed and shown many times from various Toyota OMs. At least the Toyota engineers give the user some discretion on bumping the viscosiy up if they want to. And they would be following the OM if they did.
https://toyota-club.net/files/faq/04-09-10_faq_oil-q_eng.htm

Notice the high end ambient recommended… 4th wave mid 2000 year engines. (38 c is about 100 f)
 
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Anything is possible. My cars computer knows the temperature, whether it’s raining or snowing, going uphill or downhill or around a corner, and a bunch of other stuff.

When it was 105°F out and I was running 0W-20 I didn’t get a warning message.

As I was discussing in a thread I started several weeks ago, my particular Mazda's ECU must know the oil pressure because when its as hot as it gets where I live, while using lower viscosity oil, the valve timing changes and power is cut where power does the most damage (hard launches and hard shifts and rapid on off throttle use). The vehicle won't burn a drop of oil with 0w20 typically, but if I trick it into not cutting power by messing with clutch switch that sends signals to the ECU about clutch use, it will stop cutting power, remove rev hang (even when hot out) and it will consume a bit of oil in the process. There's no doubt in my my mind that in many vehicles spec'd for 0w20, 0w20 is a safe enough to use viscosity ONLY because many vehicles are de-tuned to survive while running 0w20 oil. This detuning pretty much eliminates the possibility of the engine can be operated in ways that will destroy itself while using 0w20 oils.

All this to say, there are some makes out there where 0w20 is recommended and have oil consumption issues using that oil, worse in manual transmissions where the ECU has less control over engine conditions, tells me that not all cars are as detuned. Example would be Subarus, even after the low tension ring fiasco, they still seem to be burning oil after the fix, and those who just use higher viscosity ( mostly Europeans) aren't plagued with oil consumption issues regardless of what transmission.

So my verdict is yes, 0w20 is safe to use in most modern cars that spec it's use, but not because the oil itself is superior to oils with greater film thickness, but because of the OEM's removing/reducing the engines ability to operate in conditions that it will destroy itself in. Think about how dull and disconnected a new Corolla feels compared to one from 1996 that gave you all it had when you stomped on it. Even automatics were 100% predictable and responsive some 25 years ago. Put 0w20 in those old cars and drive them gently under 55mph, and they will last forever. Beat the snot out of them and the engines will burn up very very quickly. It's the tuning.
 
As I was discussing in a thread I started several weeks ago, my particular Mazda's ECU must know the oil pressure because when its as hot as it gets where I live, while using lower viscosity oil, the valve timing changes and power is cut where power does the most damage (hard launches and hard shifts and rapid on off throttle use). The vehicle won't burn a drop of oil with 0w20 typically, but if I trick it into not cutting power by messing with clutch switch that sends signals to the ECU about clutch use, it will stop cutting power, remove rev hang (even when hot out) and it will consume a bit of oil in the process. There's no doubt in my my mind that in many vehicles spec'd for 0w20, 0w20 is a safe enough to use viscosity ONLY because many vehicles are de-tuned to survive while running 0w20 oil. This detuning pretty much eliminates the possibility of the engine can be operated in ways that will destroy itself while using 0w20 oils.

All this to say, there are some makes out there where 0w20 is recommended and have oil consumption issues using that oil, worse in manual transmissions where the ECU has less control over engine conditions, tells me that not all cars are as detuned. Example would be Subarus, even after the low tension ring fiasco, they still seem to be burning oil after the fix, and those who just use higher viscosity ( mostly Europeans) aren't plagued with oil consumption issues regardless of what transmission.

So my verdict is yes, 0w20 is safe to use in most modern cars that spec it's use, but not because the oil itself is superior to oils with greater film thickness, but because of the OEM's removing/reducing the engines ability to operate in conditions that it will destroy itself in. Think about how dull and disconnected a new Corolla feels compared to one from 1996 that gave you all it had when you stomped on it. Even automatics were 100% predictable and responsive some 25 years ago. Put 0w20 in those old cars and drive them gently under 55mph, and they will last forever. Beat the snot out of them and the engines will burn up very very quickly. It's the tuning.
The Skyactiv controls the oil pressure and it is controlled by a lot of inputs. One is water temperature.
https://www.hexorcism.com/16ND/sh13083/

So… you can decrease oil viscosity required if oil pressure is regulated to match the need.
 
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Why I come to this question is that all trend analyses have not shown increased element concentrations of 0W20 oils to thicker oils. Even under load on the racetrack and over 10000 kilometres, the results are sometimes better than with a 5W30 A3 oil under similar load. Since the motor is not thermally optimally tuned, you could try to control the heat balance a little better with a thinner oil.
You haven’t seen a change in “macro” UOA elements because severe wear will most assuredly result in wear particles bigger than 7u, which will pass through even really good oil filters yet are too big to ever influence a UOA.
 
Couple of things…

I only use the oil viscosity that’s stamped on the engine oil cap. The only times I’ve used something different is when the owners manual lists alternative viscosities. I.E General Motors allowing 0W-30 in cold climates, General Motors allowing 10W-30 in the LS1 V8, and Hyundai allowing a plethora of viscosities. 99% of the time I always run what’s on the oil cap. Every now and then I’ll run something different but still within the specifications in the OM.

Personally, I’d be more worried about the fuel you use over anything else. Use oil that meets the specs for your engine and make sure to purchase gasoline at a trusted station. I can’t tell you how many times I’ve seen engines carboned up, fuel injectors crusted with carbon, or burn a valve or get gummed up piston rings because the fuel was inferior.

I’ve never had an engine fail or burn oil or give me some sort of weird problem….

Second thing. Most of Mexico is not hot as in 100 degrees F hot. Northern Mexico, the Baja region (hell), and some areas along both coasts are hot, but inland is typically a moderate temp Mediterranean climate. Just had to get that out there.
 
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I only use the oil viscosity that’s stamped on the engine oil cap. The only times I’ve used something different is when the owners manual lists alternative viscosities. I.E General Motors allowing 0W-30 in cold climates, General Motors allowing 10W-30 in the LS1 V8, and Hyundai allowing a plethora of viscosities.
0w30 and 10w30 oil are the same viscosity at operating temperature
 
So… you can decrease oil viscosity required if oil pressure is regulated to match the need.
Lubrication quality depends on getting the proper oil flow/supply to the moving parts - and also the viscosity/HTHS of the oil can matter too to provide adequate MOFT between parts. That's why positive displacement oil pumps are used in engines - to ensure proper oil supply to all parts of the oiling system. Oil pressure is just an artifact of moving X gpm of oil at y viscosiy through a fixed flow resistance. Of course oil pressure in some modern engines is important for actuating can timing, displacement on demand, etc.
 
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No they are not. The engine is not designed “for” a grade here, but it may designed to tolerate one. That engine will operate just fine on an oil with a higher HT/HS as long as the winter rating is appropriate for the expected starting temperature.

Even more so no engine is designed for a certain winter rating, that is silly.
Silly? You must not be familiar with the engine oiling changes that have occurred in the last 8 years with the GM LS engines. Oiling passages cast in the block for oiling on the SUCTION side of the oiling system. To be clear, my statement is relevant to GM. Don’t know or care about any other manufacturers nor do I care what oil YOU use. I use what I want and typically reflects the manufacturer’s design and recommendations. After 30 years in First Responder vehicle fleet management if nothing else you learn to use what the manufacturer recommended. Especially critical when/if filing a warranty claim. Losing funds because of denied warranty claims will ensure a Fleet Manager has a quick exit…. EDIT: Manufacturers’ Fleet Representatives called on our shop and and were the lifeline for warranty claim settlement. When they saw the adherence to their recommendations every claim was settled and they more times than not extended manufacturer’s courtesy towards out of warranty repair costs in that same vein….
 
Silly? You must not be familiar with the engine oiling changes that have occurred in the last 8 years with the GM LS engines. Oiling passages cast in the block for oiling on the SUCTION side of the oiling system. To be clear, my statement is relevant to GM. Don’t know or care about any other manufacturers nor do I care what oil YOU use. I use what I want and typically reflects the manufacturer’s design and recommendations. After 30 years in First Responder vehicle fleet management if nothing else you learn to use what the manufacturer recommended. Especially critical when/if filing a warranty claim. Losing funds because of denied warranty claims will ensure a Fleet Manager has a quick exit…. EDIT: Manufacturers’ Fleet Representatives called on our shop and and were the lifeline for warranty claim settlement. When they saw the adherence to their recommendations every claim was settled and they more times than not extended manufacturer’s courtesy towards out of warranty repair costs in that same vein….
Yes silly. And your response does nothing to change that.
 
Lubrication quality depends on getting the proper oil flow/supply to the moving parts - and also the viscosity/HTHS of the oil can matter too to provide adequate MOFT between parts. That's why positive displacement oil pumps are used in engines - to ensure proper oil supply to all parts of the oiling system. Oil pressure is just an artifact of moving X gpm of oil at y viscosiy through a fixed flow resistance. Of course oil pressure in some modern engines is important for actuating can timing, displacement on demand, etc.
And in the end it’s about keeping parts separated through the oil film. Not about pressure as such.

A tremendous amount of misunderstanding and ignorance displayed in this thread which is being translated into stated convictions which are incorrect.
 
Silly? You must not be familiar with the engine oiling changes that have occurred in the last 8 years with the GM LS engines. Oiling passages cast in the block for oiling on the SUCTION side of the oiling system. To be clear, my statement is relevant to GM. Don’t know or care about any other manufacturers nor do I care what oil YOU use. I use what I want and typically reflects the manufacturer’s design and recommendations. After 30 years in First Responder vehicle fleet management if nothing else you learn to use what the manufacturer recommended. Especially critical when/if filing a warranty claim. Losing funds because of denied warranty claims will ensure a Fleet Manager has a quick exit…. EDIT: Manufacturers’ Fleet Representatives called on our shop and and were the lifeline for warranty claim settlement. When they saw the adherence to their recommendations every claim was settled and they more times than not extended manufacturer’s courtesy towards out of warranty repair costs in that same vein….
So, how is an engine “designed” for a different viscosity?

If engines are “designed“ for a specific viscosity, then how can a manufacturer change the viscosity recommendation years after the engine was built (as Toyota did with several of theirs, covering several model years)?

If engines are “designed” for a specific viscosity, why aren’t the part numbers for critical components like bearings in those engines different across the years in which the different viscosity was specified?

If engines are “designed” for a specific viscosity - then how do they operate while the oil is warming from ambient temperature, where it is hundreds of times more viscous, to operating temperature?
 

0W20 for good protection?​

I quoted this from your title. I'd say "adequate" for protection, I recall reading many times on this forum quotes from owners manuals and other literature the word "adequate" used a lot when a 20 grade oil was mentioned. My bet is that word still holds true. Me I want better than adequate and stopped using 20 grade oils in both my Jeeps. I'll skip the hide emoji this time. ;)
 
I quoted this from your title. I'd say "adequate" for protection, I recall reading many times on this forum quotes from owners manuals and other literature the word "adequate" used a lot when a 20 grade oil was mentioned. My bet is that word still holds true. Me I want better than adequate and stopped using 20 grade oils in both my Jeeps. I'll skip the hide emoji this time. ;)


The choice of word might be a legal matter.
 
I quoted this from your title. I'd say "adequate" for protection, I recall reading many times on this forum quotes from owners manuals and other literature the word "adequate" used a lot when a 20 grade oil was mentioned. My bet is that word still holds true. Me I want better than adequate and stopped using 20 grade oils in both my Jeeps. I'll skip the hide emoji this time. ;)
Yep. The first time I saw that was from Honda. A 20-grade was essentially the last iteration that could be applied to what were traditional engine designs. After that it took redesign to permit thinner grades to be used. But adequate wear isn’t a word I wish to use for my vehicles since I do not place fuel economy as my primary and sole concern.
 
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