Will the chemistry of low visc oils catch up to physical properties of thicker ones

[StevieC]

I don't think there can be a blanket statement for all engines that thicker or thinner is better without a trend established on UOA's for a particular oil for a particular engine. I had great success running 5w20 in my Dodge Journey's engine which called for 5w30 previously. 4ppm Iron and 0 on all other metals after 9K is excellent and would indicate that parts are being kept separated with this thin oil. Would it have done better on a 30wt as previously spec'ed for this engine? I doubt it considering how low my numbers were.

What I'm getting at is that I would start with the owners manual, establish a trend and the move up a weight and see how that affects the trend. Then switch brands and try various weights and see how that affects the trend. All engines are different, all oils are different and we can't blanked that 20 weights are evil and part of CAFE conspiracy and 30 or 40 weights are the way to go without proper evidence. That's my take on it.

 

[tig1]

Originally Posted by wemay
This is not meant as an open invitation to read about your preferences, anecdotes and hatred for CAFE. ðŸ‘

We know that lower viscosity oils offer better fuel mileage, and as a cost, less protection. Both to varying degrees and possibly at insignificant levels where an xw20 vs xw30 is concerned.

But since the march towards even lower viscosity is the industry trend, will the chemistry of these oils ever match the physical properties of the thicker oils where wear is considered? Are we there yet? Is it even possible? Has reliance on antiwear tech reached that point?



We all don't know that lower vis oils offer less protection. I have used 0-20 for the last 460K + in my last 3 Ford engines and I use it for the outstanding protection M1 0-20 gives me.

 

[PimTac]

Originally Posted by StevieC
I don't think there can be a blanket statement for all engines that thicker or thinner is better without a trend established on UOA's for a particular oil for a particular engine. I had great success running 5w20 in my Dodge Journey's engine which called for 5w30 previously. 4ppm Iron and 0 on all other metals after 9K is excellent and would indicate that parts are being kept separated with this thin oil. Would it have done better on a 30wt as previously spec'ed for this engine? I doubt it considering how low my numbers were.

What I'm getting at is that I would start with the owners manual, establish a trend and the move up a weight and see how that affects the trend. Then switch brands and try various weights and see how that affects the trend. All engines are different, all oils are different and we can't blanked that 20 weights are evil and part of CAFE conspiracy and 30 or 40 weights are the way to go without proper evidence. That's my take on it.





I agree. The usage of the vehicle and the demands placed on it should determine the oil grade as well. As an example, Two people owning the same pickup truck. One uses it for commuting and the other tows heavy trailers over the mountains.

For most driving conditions, today's modern engines loaf around at 1500-2000 rpms. It's a far cry from yesterday's engines.

 

[demarpaint]

Originally Posted by StevieC
I don't think there can be a blanket statement for all engines that thicker or thinner is better without a trend established on UOA's for a particular oil for a particular engine. I had great success running 5w20 in my Dodge Journey's engine which called for 5w30 previously. 4ppm Iron and 0 on all other metals after 9K is excellent and would indicate that parts are being kept separated with this thin oil. Would it have done better on a 30wt as previously spec'ed for this engine? I doubt it considering how low my numbers were.

What I'm getting at is that I would start with the owners manual, establish a trend and the move up a weight and see how that affects the trend. Then switch brands and try various weights and see how that affects the trend. All engines are different, all oils are different and we can't blanked that 20 weights are evil and part of CAFE conspiracy and 30 or 40 weights are the way to go without proper evidence. That's my take on it.


The only problem with trying that is there are many of us that have more than one vehicle, and one or more vehicles that see little use in a year. Case in point, I'm pushing 3,300 miles in 2 years on my work van. The plan was to get a second UOA at 4K miles. At the current rate it could be early winter or late spring before that happens. By the time the trend is established for one oil, let along different oils and grades it could take a decade or more. Sometimes unfortunately you have to go with an educated guess, or hunt for the same vehicle used under similar conditions and use that UOA as a cheat sheet, certainly not the best way to go.

 

[StevieC]

Originally Posted by demarpaint
The only problem with trying that is there are many of us that have more than one vehicle, and one or more vehicles that see little use in a year. Case in point, I'm pushing 3,300 miles in 2 years on my work van. The plan was to get a second UOA at 4K miles. At the current rate it could be early winter or late spring before that happens. By the time the trend is established for one oil, let along different oils and grades it could take a decade or more. Sometimes unfortunately you have to go with an educated guess, or hunt for the same vehicle used under similar conditions and use that UOA as a cheat sheet, certainly not the best way to go.


In that case it really is moot because it's things like Rust and age based wear/tear that will claim the life of that vehicle long before engine oil weight will make a difference in such a low mileage situation.

... But you could try and guess based on other UOA's and weights / brands used for similar engines as yours.

 

[WyrTwister]

That depends on where you live . I have never quit driving a vehicle because of rust , in close to 50 years .

 

[demarpaint]

Originally Posted by StevieC
Originally Posted by demarpaint
The only problem with trying that is there are many of us that have more than one vehicle, and one or more vehicles that see little use in a year. Case in point, I'm pushing 3,300 miles in 2 years on my work van. The plan was to get a second UOA at 4K miles. At the current rate it could be early winter or late spring before that happens. By the time the trend is established for one oil, let along different oils and grades it could take a decade or more. Sometimes unfortunately you have to go with an educated guess, or hunt for the same vehicle used under similar conditions and use that UOA as a cheat sheet, certainly not the best way to go.


In that case it really is moot because it's things like Rust and age based wear/tear that will claim the life of that vehicle long before engine oil weight will make a difference in such a low mileage situation.

... But you could try and guess based on other UOA's and weights / brands used for similar engines as yours.


That hasn't been the case with my van. The paint is dead, but there is zero rust and it still runs well.

And in the case of my 2016 Rubicon with 11K miles on it, determining what oil is "best" will still take a very long time. I'm still waiting on the wear metals from break in to wash out, some claim can take up to 20K miles. lol Both are works in progress with UOA's. All kidding aside, I plan on sticking with PU 5W30 as long as I can continue to get it.

 

[StevieC]

After having run 0w30 in my 5w20 Spec'ed Santa Fe I can honestly say that I think it makes little difference in the long run unless someone was keeping their vehicle for a million miles sort of thing where this insignificant amount of metals might actually add up. That's just my experience. Even if you did see some minor increase in PPM on the wear metals on the UOA before they would actually matter would be so far out that the argument of a 20 versus a 30 or a 40 is really moot in most applications. (This doesn't include certain considerations for higher than normal fuel dilution, high performance engines, or racing applications)

 

[kschachn]

Originally Posted by PimTac
The term 0w-water shows your bias.

Or just a fundamental misunderstanding of the basics.

I wonder if the 0W-40 I use in my BMW is "water"?

 

[benjy]

most drivers trade by 100,000 miles, its after that that wear + tear shows up IMO + your prolly lucky if your tranny lasts that long especially if its a CVT. i alwals use at least 10-30 in my vehicles in Pa. girlfriends new in 13 malibu LS 2.5L was drinking the spec 5-20 dexos I oil, changed to a 10-30 + it was cured!!! many don't factor in the temperature + driving types they do when selecting oil viscosity + change intervals as they want to cheap out using the suspect oil monitor!!

 

[PimTac]

Originally Posted by benjy
most drivers trade by 100,000 miles, its after that that wear + tear shows up IMO + your prolly lucky if your tranny lasts that long especially if its a CVT. i alwals use at least 10-30 in my vehicles in Pa. girlfriends new in 13 malibu LS 2.5L was drinking the spec 5-20 dexos I oil, changed to a 10-30 + it was cured!!! many don't factor in the temperature + driving types they do when selecting oil viscosity + change intervals as they want to cheap out using the suspect oil monitor!!



Take a breath. Paragraphs.

 

[wemay]

Originally Posted by benjy
...many don't factor in the temperature + driving types they do when selecting oil viscosity + change intervals as they want to cheap out using the suspect oil monitor!!


The current run of 5w20 in my Sportage is the last of the Xw20 stash. All i have on hand right now is 5w/10w30 with more 10w30 on it's way from a rollback at Walmart.com for Mobil Super Syn. The temperature excerpt in my manual is what steered me in that direction, as you allude to. I'm sure many on here do the same.

 

[CR94]

I don't think the title question is reasonable. An apple can never out-peach a peach, but that doesn't mean it isn't worth having.

 

[wemay]

Originally Posted by CR94
I don't think the title question is reasonable. An apple can never out-peach a peach, but that doesn't mean it isn't worth having.


Interesting way of looking at it, and by no means was i implying they were competing on equal footing. There are compromises with each. I was just wondering if the lower viscosity additive technology would ever be capable of matching higher grade oils in wear protection. Strictly through the use of ever increasingly sophisticated additive technology. But i also thought about this throughout the day... if that technology is available to the lower visc, it would also be available to the thicker oils.

Thanks to everyone who participated.

 

[Garak]

I think what we have to look at, both from a fuel economy and a wear reduction standpoint, is the law of diminishing returns. There's only so much fuel economy to be had based upon reduction in friction and reducing pumping losses, and the chemistry can also go so far.

 

[Shannow]

Originally Posted by MolaKule

I.e., are engine bearings, rings, and camshafts being replaced at a frantic pace that can be traced to lower viscosity oils being the cause of failure and or replacement?


Could similarly ask which components are being redesigned ?

Bearing for instance are, and have been under heavy re-development, with materials and polymers to...extend life.

Why do they now need life extension when engines have run forever in the past ?

Yes, stop start is part of it...but that's the same bucket.

 

[Cujet]

Originally Posted by PimTac


The term 0w-water shows your bias.


It sure does!

The problem below is completely preventable with higher viscosity and more frequent changes.

 

[fdcg27]

The real question is whether an engine will take a car to its natural life of 200K+ and fifteen or twenty years using thinner grades.
That question has already been answered in practice.
As Shannow noted in this thread and as many others have in many other threads throwing a vehicle away when it has many more tens of thousands of miles of working life in its engine at the expense of greater fuel use during its useful life makes no economic sense.
I'm not going to spend more on fuel just so that someone else can buy a good engine from a yard.

 

[PimTac]

Originally Posted by Cujet
Originally Posted by PimTac


The term 0w-water shows your bias.


It sure does!

The problem below is completely preventable with higher viscosity and more frequent changes.








It could be argued that using a higher viscosity oil just masked the underlying problem, just like putting in a thicker grade of oil to mask valve clatter on a older car before selling it.

 

[turtlevette]

I think you really have to break down what's happening to the microscopic level. I don't believe hydrodynamic action of a bearing is the same as the piston ring. Some people like shannow don't recognize that. It boils down to what you've been trained in.

The bearing creates a phenomenon where the shaft is trying to climb a wall or wave that's created by the curvature in the system. The ring against wall and or lifter on cam creates a bulldoze push effect, which in my opinion doesn't as readily create a hydrodynamic condition. Furthermore you have to look at how well the lubricant bonds or sticks to the metal avoiding a scrape off or shear off effect resulting in metal on metal. This is why zddp works so well. You have a true bond. So consider an oil that sticks or actually bonds so well that you don't need zddp. Think about whether the oil movement in the boundary is laminar or turbulent. I think stuff like that matters and depends on the molecular makeup. I refuse to believe that oil is oil.

So no. I don't think it's as simple as just considering the viscosity.