0W-16 Strength & Durability

Status
Not open for further replies.
By "in grade," I would be asking.. does it retain its HTHS or possibly other SAE J300 properties that would keep it as a 20, a 30, a 40.. a 50, a 16. So.. would the oil become "less than," which is why some believe you need to go thicker.

Without making this thread all about me. I frequently take long, long, long, long high speed (highway) trips, with city driving at the end, my car can be in motion for 15 hours at a time. 10+ hours, even tonight. I change my oil somewhat frequently but I usually get it right to 5k OCI on average.. should I worry about my oil protecting less?

Lately I've been using 5W-30 and participating in HPL research of what filters look like with their product.
In grade is 40c to 100c. Cab service cars last a very long time because they do not turn off their engines. Highway is the nicest thing you can do for your engine IMO.
 
Air flow into the engine compartment helps dissipate heat off the engine. Heat is also lost through the oil pan. Most modern cars have a water-to-oil cooler which helps keep the oil temperature down. Just like the link I posted above, even in a modern engine using a water-to-oil cooler, the outside ambient air temperature effect can still be seen on the oil temperature.

Water-to-oil coolers, and air-to-oil coolers certainly help with the thinner used oils, as part of their use success is to control the oil temperature so they don't thin down to the point of causing engine damage. Keeping 16 at say 180F would be like running 30 at 200 F as an example.
Water to oil coolers are also water to oil heaters, cause water beats the oil to operating temperature.
 
By the way my 2019 Miata takes 0w-20. In Europe they give two choices of Mazda oil 0w-20 and 5w-30. Guess what oil viscosity you think the Miata guys swing to.
I'd say 5W-30 if they understand the relationship between MOFT and viscosity. If they want 1 more HP or 0.01 more MPG, then maybe some go for the 0W-20.
 
Last edited:
In grade is 40c to 100c.
Oil grades per SAE J300 are defined at 100C only. And of course the "W" rating, which is a different viscosity rating method. There is no KV40 rating in J300 ... that is an oil manufacturer spec only. J300 also defines HTHS viscosity at 150C.
 
Last edited:
You can overdo any thing. The engine bearings are designed for oil flow. Every exit for the oil PSI is in parallel with with one source, the oil pump. Too thin of oil has problems as too thick. There is CAFE and there is what the engine is engineered for. 30% of engine cooling depends on the oil flow. Oil temperature varies inside the engine. IMO the engineered oil flow is directly proportional to viscosity even though we are talking about a positive displacement oil pump because there are multiple outlets for that oil can go. There is a perfect viscosity for every engine. The only way to determine is the PSI. I always think of the main bearings but the pistons have oil jets that spray under the pistons. Same as low SAPS. Sulfated ash is used in the engine valve seats and piston rings. Always a happy medium.
Bearings are self pumping, the oil pump just ensures there is sufficient supply at the inlet, @Shannow has written on this extensively in the past and it may be worthwhile to search for his posts on the subject to properly understand it.

Piston cooling jets are not something that are universally used either, in fact they have historically been relatively uncommon. Cylinder wall lubrication is achieved by oil getting squeezed out from the rod bearings.

Since viscosity varies with temperature, there is no perfect viscosity for a given engine. Viscosity changes over the operating regime depending on what the equipment is doing. Engines are incredibly tolerant of massive changes in viscosity, and have to be due to that fact.
 
Okay, well explained.. I may need to read it several times but, if it is hot out and driven hard, the engine oil may be different viscosity than what it says it normally is.



Just so I'm with you.. because of what it is tested/rated/certified with, would be the base from which it sees that dramatically different viscosity?
Temperature, temperature dictates the viscosity. And yes, engines are tested at a huge spectrum of temperatures to ensure that what is recommended by the manufacturer is adequate in all of them.
 
Only if the oil is thick enough to ensure that moving parts don't excessively rub on each other. The thinner the MOFT becomes, the more rubbing contact will occur. It's the whole backbone of tribology and the basic correlation between oil viscosity and MOFT (film thickness) that has been true for 100 years.
Yes, and this brings forth the discussion about the shift from hydrodynamic to mixed boundary with thinner oils and the additives used to prevent excessive wear under these conditions. Those were some great discussions we had on that subject a few years ago now.
 
Bearings are self pumping, the oil pump just ensures there is sufficient supply at the inlet, @Shannow has written on this extensively in the past and it may be worthwhile to search for his posts on the subject to properly understand it.

Piston cooling jets are not something that are universally used either, in fact they have historically been relatively uncommon. Cylinder wall lubrication is achieved by oil getting squeezed out from the rod bearings.

Since viscosity varies with temperature, there is no perfect viscosity for a given engine. Viscosity changes over the operating regime depending on what the equipment is doing. Engines are incredibly tolerant of massive changes in viscosity, and have to be due to that fact.

There are a lot of hydraulics in the Skyactiv, not just the main bearings.
 
Water-to-oil coolers, and air-to-oil coolers certainly help with the thinner used oils, as part of their use success is to control the oil temperature so they don't thin down to the point of causing engine damage. Keeping 16 at say 180F would be like running 30 at 200 F as an example.

One explanation is that engines designed for 0w-16 operate at lower OIL temperature compared to those designed for higher viscosity oil. For example, at 188F the viscosity of 0W-16 is about 10 cSt -- the optimum value for most engines. Whereas a XW-30 oil reaches that viscosity at 212F. So at least for journal bearings and cam lobes which aren't directly exposed to combustion temperatures, a 0W-16 oil could work fine provided the engine oil temperature is kept in check.

This is interesting. I understand how running the oil at lower temps can be beneficial due in part to its thicker viscosity. Over the year or so that I've been here, that concept has been brought up with the idea that running an engine colder, such as when doing short trips, actually affords better protection.

So, with oil running cooler for better protection, might it also be true that cooler oil temps prevent the oil from getting hot enough to burn off water, gasses, and other contaminants which, in turn, degrades the effectiveness of the oil and reduces its long-term viability and making 10,000-mile OCIs problematical? Any thoughts on this, any experience with the issue ... or is it even a consideration?
 

There are a lot of hydraulics in the Skyactiv, not just the main bearings.
Yes, my 6.4L has them too, but my old 5.4L Ford didn't, none of my Windsors had them, and my 5.7L doesn't have them.
 
Yes, my 6.4L has them too, but my old 5.4L Ford didn't, none of my Windsors had them, and my 5.7L doesn't have them.
Just one of my reasoning not to go thicker. Modern engines are loaded with hydraulics. The variable valve timing chain is another.
 
Only if the oil is thick enough to ensure that moving parts don't excessively rub on each other. The thinner the MOFT becomes, the more rubbing contact will occur. It's the whole backbone of tribology and the basic correlation between oil viscosity and MOFT (film thickness) that has been true for 100 years.
In the dino years. I am SP oils now.
 
Just one of my reasoning not to go thicker. Modern engines are loaded with hydraulics. The variable valve timing chain is another.
Aye, but many of the engines with all that stuff spec thick oil because of their intended usage profile. My old E39 M5, that engine on the pre 03/00 cars spec'd 10w-60, later cars (like mine) called for LL-01. That engine was wickedly complex, had piston cooling jets, dual VANOS, multiple variable oil pump pick-up points, 8 throttle bodies...etc, Ford spec'd 5w-20 and 5w-50 for the same engine depending on whether you ordered the "track pack" or not, and that was a DOHC dual VVT V8.

My 6.4L spec's 0w-40 and of course has the jets and VCT (though being a pushrod engine, it's less complex in that department).

Funny enough, that M5 had issues getting the oil up to temp in the winter. It had a large thermostatically controlled heat exchanger in the valley and a 7L sump and with everything aluminum, it really struggled to get the oil up to even 80C.

I'm not saying this to try and sway your decision, just point out that those criteria alone do not dictate a lower viscosity.
 

Attachments

  • cluster01.jpg
    cluster01.jpg
    295 KB · Views: 16
Only if the oil is thick enough to ensure that moving parts don't excessively rub on each other. The thinner the MOFT becomes, the more rubbing contact will occur. It's the whole backbone of tribology and the basic correlation between oil viscosity and MOFT (film thickness) that has been true for 100 years.
IMO You start your engine. The oil is way too thick at 0w. Then while driving and the temperature warm up to operating temperature. The base oil synthetic gives you some viscosity index but the rest need some VII. In reality wear happens when you first start your engine. The more RPM the engine gets the safer when at operating temperature as far as MOFT.
 
IMO You start your engine. The oil is way too thick at 0w. Then while driving and the temperature warm up to operating temperature. The base oil synthetic gives you some viscosity index but the rest need some VII. In reality wear happens when you first start your engine. The more RPM the engine gets the safer when at operating temperature as far as MOFT.
Keep in mind, the number in front of the W (Winter rating) is an indication of the oil's ability to be below two threshold numbers measured at two temperatures 5 degrees apart from each other. It's not an indication of the oil's viscosity above those temperatures.

Example:
A 0W-40 has to meet the CCS (-35C) and MRV (-40C) requirements for the 0W-xx designation, which, if you look at J300, are 6,200cP and 60,000cP respectively.
SAE J300 - Current.png


Now, a 5w-20 doesn't have to meet those same requirements, and in fact, because of it carrying the 5W-xx Winter designation, we know it's thicker at -35C than 6,200cP, otherwise it would have passed and been labelled a 0w-20.

BUT, at some point, perhaps one not too far above -30C, that 5w-20 is thinner, and gets continually moreso than the 0w-40.
 
Keep in mind, the number in front of the W (Winter rating) is an indication of the oil's ability to be below two threshold numbers measured at two temperatures 5 degrees apart from each other. It's not an indication of the oil's viscosity above those temperatures.

Example:
A 0W-40 has to meet the CCS (-35C) and MRV (-40C) requirements for the 0W-xx designation, which, if you look at J300, are 6,200cP and 60,000cP respectively.
View attachment 84112

Now, a 5w-20 doesn't have to meet those same requirements, and in fact, because of it carrying the 5W-xx Winter designation, we know it's thicker at -35C than 6,200cP, otherwise it would have passed and been labelled a 0w-20.

BUT, at some point, perhaps one not too far above -30C, that 5w-20 is thinner, and gets continually moreso than the 0w-40.
Base oil is synthetic with 0w, cannot be group 1 or group 2. I think they can call some synthetic group 3 and GTL is group 3+
Why is that important? The 0w synthetic is the starting base oil viscosity and changing the viscosity index +VII gets you where you need to go at operating temperature. How small the VII can go or how wide the VII can go… well the HTHS is a minimum for your chart at high temperature. And that shows the high end of the VII quality. Since I do not go that high. Really 40 c is over 100 f and the viscosity index improvers are not designed for the most critical part of oil protection, the engine cold start. It really does not matter how low the oil can go and still crank.
 
Last edited:
Remember why the HTHS viscosity parameter was invented. It's because the oil can run at near 150C in the journal bearings while it's shearing at a high rate, even though the oil in the sump is at 100-120C. So you don't have to be screaming down the Autobahn or on a track to get the oil at 150C in the bearings. In those cases, you better have way more HTHS viscosity than 2.6 cP.
My sump runs 133C after two hours of mixed driving in the summer.
 
Status
Not open for further replies.
Back
Top