Your Opinion on Choosing an Oil Grade

[Sequoiasoon]

First if you use that over recommended, we can say "it's totaled".

I trying to stand in the oil aisle and use this method.

Actually with all the sales stash varieties I can do that in my garage next time.

 

[FlyingTexan]

Their meaning of “lifetime” and your meaning of “lifetime” aren’t the same so I guess that depends what we are calling “life.” Are you expecting one transmission to last for your entire life on earth?

If an oil is suitable for use then it’s suitable for use

It's amazing how it wasn't suitable before but with no changes now is

 

[ATex7239]

It's amazing how it wasn't suitable before but with no changes now is

If it wasn’t suitable then why would they list it as an option in the places where CAFE isn’t a requirement? Don’t you think they would exclude it altogether?

 

[ATex7239]

If it wasn’t suitable then why would they list it as an option in the places where CAFE isn’t a requirement? Don’t you think they would exclude it altogether?

Also, I would like to add to my comment: manufacturers across the board (every industry) would probably prefer not to have to change, update, innovate, adapt, etc. But that is not the world we live in. CAFE isn’t going anywhere. Manufacturers are going have to adapt to the standards. This is not specific to the automotive industry. Every industry has to deal with standards, codes, and regulations. This is nothing new.

 

[Hohn]

The engine isn't nearly as picky about viscosity grades as we BITOGers are.

While I disagree with much of Dr. Haas' writings, he's not wrong that every oil is too thick when it's not warmed up. At some temperature, the "w" grade matters much less than the main grade. In a warm climate, this point is below almost all regular oil temps you encounter.

A thick 20 grade at 90°C might be significantly thicker than a light-end 30 grade at 105°. Which means that staying with the "thin" oil means running "thick" oil in the context of persistently low average oil temps.

Remember, the grades are just snapshots at a particular reference temperature. The actual running viscosity depends on your temperature and your usage. This is why the newer hybrids are calling for the 0w-12 and even 0w-8 oils. It's because those oil are only "so thin" in the context of the KV100. If you monitor the average oil temperatures of these hybrids, you'll find that at the common temperature, these thin oils are much closer to a 20 grade's viscosity in a constant-run application.

One could argue that even your driving style matters in a street car. If you drive aggressively and get poor MPG vs other drivers, you probably have hotter oil temperatures than those drivers, too, and should have an oil that's a higher SAE grade.

Conversely, if you drive like the proverbial little old lady, maybe a 20 grade is a "thick" oil for you.


Which sort of raises the question as to whether we should all install oil coolers so we can run thinner oils and still have them be thicker in the engine, eh?

 

[Glenda W.]

The engine isn't nearly as picky about viscosity grades as we BITOGers are.

While I disagree with much of Dr. Haas' writings, he's not wrong that every oil is too thick when it's not warmed up. At some temperature, the "w" grade matters much less than the main grade. In a warm climate, this point is below almost all regular oil temps you encounter.

A thick 20 grade at 90°C might be significantly thicker than a light-end 30 grade at 105°. Which means that staying with the "thin" oil means running "thick" oil in the context of persistently low average oil temps.

Remember, the grades are just snapshots at a particular reference temperature. The actual running viscosity depends on your temperature and your usage. This is why the newer hybrids are calling for the 0w-12 and even 0w-8 oils. It's because those oil are only "so thin" in the context of the KV100. If you monitor the average oil temperatures of these hybrids, you'll find that at the common temperature, these thin oils are much closer to a 20 grade's viscosity in a constant-run application.

One could argue that even your driving style matters in a street car. If you drive aggressively and get poor MPG vs other drivers, you probably have hotter oil temperatures than those drivers, too, and should have an oil that's a higher SAE grade.

Conversely, if you drive like the proverbial little old lady, maybe a 20 grade is a "thick" oil for you.


Which sort of raises the question as to whether we should all install oil coolers so we can run thinner oils and still have them be thicker in the engine, eh?

Ah yes the adventures of Dr Haas. Really is a pity what he did to that Navigator. I especially feel bad for whoever the current owner is….

 

[ATex7239]

The engine isn't nearly as picky about viscosity grades as we BITOGers are.

While I disagree with much of Dr. Haas' writings, he's not wrong that every oil is too thick when it's not warmed up. At some temperature, the "w" grade matters much less than the main grade. In a warm climate, this point is below almost all regular oil temps you encounter.

A thick 20 grade at 90°C might be significantly thicker than a light-end 30 grade at 105°. Which means that staying with the "thin" oil means running "thick" oil in the context of persistently low average oil temps.

Remember, the grades are just snapshots at a particular reference temperature. The actual running viscosity depends on your temperature and your usage. This is why the newer hybrids are calling for the 0w-12 and even 0w-8 oils. It's because those oil are only "so thin" in the context of the KV100. If you monitor the average oil temperatures of these hybrids, you'll find that at the common temperature, these thin oils are much closer to a 20 grade's viscosity in a constant-run application.

One could argue that even your driving style matters in a street car. If you drive aggressively and get poor MPG vs other drivers, you probably have hotter oil temperatures than those drivers, too, and should have an oil that's a higher SAE grade.

Conversely, if you drive like the proverbial little old lady, maybe a 20 grade is a "thick" oil for you.


Which sort of raises the question as to whether we should all install oil coolers so we can run thinner oils and still have them be thicker in the engine, eh?

If you look at the diagrams of the cooling/heating system for the newer Toyota engines you’ll see thought was clearly put into accounting for the use of lower grades. Which is the point I’ve been trying to make with some folks lately. If an engine isn’t able operate within reasonable parameters with the oil that is recommended then it’s a bad design.

 

[kschachn]

Which sort of raises the question as to whether we should all install oil coolers so we can run thinner oils and still have them be thicker in the engine, eh?

For what reason other than a quite small reduction in fuel consumption?

 

[Hohn]

For what reason other than a quite small reduction in fuel consumption?

To allow a thinner cold cranking oil to have better “warm” viscosity by not being as warm. This would seem to oxidation benefits as well.

 

[FlyingTexan]

Also, I would like to add to my comment: manufacturers across the board (every industry) would probably prefer not to have to change, update, innovate, adapt, etc. But that is not the world we live in. CAFE isn’t going anywhere. Manufacturers are going have to adapt to the standards. This is not specific to the automotive industry. Every industry has to deal with standards, codes, and regulations. This is nothing new.

Which has absolutely zero to do with the point at hand of which is better for the motor. Not what's best for the tree huggers or govt regulations. I don't care if CAFE is going anywhere or not. Stating that is only admitting my point. It's a regulation not a best practice.

 

[FlyingTexan]

If you look at the diagrams of the cooling/heating system for the newer Toyota engines you’ll see thought was clearly put into accounting for the use of lower grades. Which is the point I’ve been trying to make with some folks lately. If an engine isn’t able operate within reasonable parameters with the oil that is recommended then it’s a bad design.

Temp limits are not the same thing as shear strength and bearing tolerances. You can keep it within temp but shearing the oil with high output.

 

[FlyingTexan]

If it wasn’t suitable then why would they list it as an option in the places where CAFE isn’t a requirement? Don’t you think they would exclude it altogether?

Because the liability ends at the end of the warranty. Zero people involved are going to say a 0w20 magically protects on the level of the higher HTHS fluids it was originally designed for. Not only does it not protect as well but it doesn't protect as long and has a slew of other known issues like being too thin for effective seals. Again, if it was so great for the consumer why do they tell me the transmission is good for life? Because it's the life of their warranty they're worried about.

 

[Hohn]

Temp limits are not the same thing as shear strength and bearing tolerances. You can keep it within temp but shearing the oil with high output.

How exactly does one shear the oil with “high output”?

 

[OilUzer]

To allow a thinner cold cranking oil to have better “warm” viscosity by not being as warm. This would seem to oxidation benefits as well.

Unless things have changed, my understanding is that the reason some cars or trucks have oil cooler, is to keep the engine oil from getting too hot (for obvious reasons) and not for cooling the oil to "warm" or cooler temps in order to use a thinner oil. In general, they also want the engine oil and water temps tracking for efficiency purposes ...

Do hybrids have oil coolers for the purpose of running a thinner oil for CAFE or any other reasons?
Other than that (i.e. small mpg gain), the oxidation reason seems implausible! but I am not familiar with hybrid designs either.

 

[ATex7239]

Temp limits are not the same thing as shear strength and bearing tolerances. You can keep it within temp but shearing the oil with high output.

The Toyota A25A and M20 engines have been out since 2018 with 0W16. No known bearing issues thus far. Appears Toyota got the design right.

 

[ATex7239]

Which has absolutely zero to do with the point at hand of which is better for the motor. Not what's best for the tree huggers or govt regulations. I don't care if CAFE is going anywhere or not. Stating that is only admitting my point. It's a regulation not a best practice.

It has everything to do with it. The change to lower grades (per your post - #42) is all about CAFE. You don’t care about CAFE but auto manufacturers must. Naming calling and complaining isn’t going to change that fact.

 

[ATex7239]

Because the liability ends at the end of the warranty. Zero people involved are going to say a 0w20 magically protects on the level of the higher HTHS fluids it was originally designed for.

I never suggested that lower grades protect better. I said suitable for use is suitable for use. Or in other words - good enough is good enough.

If a manufacturer isn’t recommending a suitable (good enough) oil then there are two options: update the design accordingly or recommend something else. It’s a simple concept. They can adapt or perish.

Not only does it not protect as well but it doesn't protect as long and has a slew of other known issues like being too thin for effective seals.

If the engine wasn’t designed properly, yes.

Again, if it was so great for the consumer why do they tell me the transmission is good for life? Because it's the life of their warranty they're worried about.

Everything has a usable life expectancy (eg, how long will it reasonably last.) Mattresses, appliances, clothing, food, shoes, HVAC units, vehicles, electronics, etc. If your expectancy is greater than the standard well then plan accordingly. But manufacturers and industries are not tailoring to specific individuals, they are tailoring to the masses. And the masses do not keep things forever. You asked why. That’s why. It is what it is.

 

[kschachn]

To allow a thinner cold cranking oil to have better “warm” viscosity by not being as warm. This would seem to oxidation benefits as well.

I don’t understand. That doesn’t makes sense to me.

 

[Hohn]

I don’t understand. That doesn’t makes sense to me.

Probably because it is terribly written. My apologies. Think of having an oil thermostat and theoretically infinite oil cooling capacity. That can cap oil temps and considering the effect of capping them at 180F vs 210F. The lower temp is effectively thicker oil and maintains viscosity when "hot" without bringing any penalty for cold cranking.

Instead of using higher viscosity to manage hotter temps, you could invert that and use lower temps to obviate the need for higher viscosity. And running cooler peak oil temps should slow the rate of oxidation considerably as well.

 

[SC Maintenance]

Probably because it is terribly written. My apologies. Think of having an oil thermostat and theoretically infinite oil cooling capacity. That can cap oil temps and considering the effect of capping them at 180F vs 210F. The lower temp is effectively thicker oil and maintains viscosity when "hot" without bringing any penalty for cold cranking.

Instead of using higher viscosity to manage hotter temps, you could invert that and use lower temps to obviate the need for higher viscosity. And running cooler peak oil temps should slow the rate of oxidation considerably as well.

I read it, and I understand what you were trying to say, but it still made no sense. You can't command your oil to stay at a lower temperature so its thicker.

Your engine oil temp is going to be what its going to be under any given use, hence a 30 weight oil will always have a higher viscosity than a 20 weight oil at the same temp.