Another 0w16 Post, but....

[ZeeOSix]

Not so fast. The 0w16 was developed solely for "efficiency" purposes. It's not some magical lube that's better then the rest. Two realms to analyze, efficiency and lubrication. A good mix of the two is good, but I am not so interested in getting +0.001 mpg's. A SAE20 is likely better than a 0w16 for my specific use/env.

Pull up the film strength of a sae20 vs a 0w16 at say 250F, what do you get?

Film strength relates to how well the anti-friction / anti-wear coatings on moving parts keeps them from wearing when contact occurs. Film strength is not related to oil viscosity, that is the film thickness (ie, MOFT) between parts. Film strength is dependent on the formulation, not the viscosity.

I would think that these xW-8 and xW-16 oils have more anti-friction / anti-wear additives to make up for the lack of film thickness due to viscosity.

https://www.machinerylubrication.com/Read/30835/lubricant-film-strength

 

[ZeeOSix]

?? The bottom side of a piston never gets to 250F ?

Piston dome and ring/ring land area temps are dependent on the engine load and load duration. A car on the track will have much higher piston dome area temps then when it's cruising to the grocery store. It's a harsh environment for oil, and engines with under piston oil squirters help mitigate temps in that area.

 

[aquariuscsm]

From what I understand (I'm thinking from Shannow maybe?) viscosity is what keeps the moving parts from touching, and the add pack kicks in as a safety margin in case the oil film is breached? Heck I may have that all wrong thought.

 

[ZeeOSix]

How is this measured for motor oils?

540Rat wear scar machine ... LoL.

 

[ZeeOSix]

From what I understand (I'm thinking from Shannow maybe?) viscosity is what keeps the moving parts from touching, and the add pack kicks in as a safety margin in case the oil film is breached? Heck I may have that all wrong thought.

It's all in the Machinery Lubrication link I posted above. You have it right.

 

[ZeeOSix]

If it makes you feel better, then use 5w30 I mean I doubt anyone has any real statistical data on shortened or lengthened engine lives or wear in anycase. It's your warranty but I doubt it would come to that...

I'd go with at least a xW-20 over xW-16, and xW-30 in AZ probably fine too.

 

[ZeeOSix]

I switch oil grades for "winter". I change oil only 2x yearly and dont care about mileage.

What grade for summer and what grade for winter? Why not just run a 0W-xx all year long if you're concerned about cold starts?

 

[haggler]

If you read the owners manual (gf has the 2018 camry 2.5 spec 0w16) it says something along the lines of "higher grade may be considered if towing or high engine load." This implies they will not void your warranty, but I believe for 0w20 they want 5k oil change intervals. International manual says a wide range of oils that can be run. As everyone has mentioned 0w16 is for CAFE, run what you want. If you are driving gently it wont matter anyway.

 

[EMPIRE]

From what I understand (I'm thinking from Shannow maybe?) viscosity is what keeps the moving parts from touching, and the add pack kicks in as a safety margin in case the oil film is breached? Heck I may have that all wrong thought.

Is it? Or does the actual oil film keep the parts from touching?

 

[ZeeOSix]

Is it? Or does the actual oil film keep the parts from touching?

Read the Machinery Lubrication article linked earlier, it explains the difference between film thickness (viscosity dependent) and film strength (AW/AF additives).

 

[EMPIRE]

What grade for summer and what grade for winter? Why not just run a 0W-xx all year long if you're concerned about cold starts?

The switch is currently on my v8. 10w30 summer (jun 1 to dec 1), 5w30 winter (dec 1 to jun 1). Been running this schedule since Feb2006 w/o regard to mileage. Engine now at 223kmi.
For the Rav I am thinking I will run 5w20 summer (cant find a sae20), 0w20 winter.

Read the Machinery Lubrication article linked earlier, it explains the difference between film thickness (viscosity dependent) and film strength (AW/AF additives).

I didn't see the link, but it's this Gool search that pops up the article.
https://www.machinerylubrication.com/Read/30835/lubricant-film-strength

 

[OilReport99]

The switch is currently on my v8. 10w30 summer (jun 1 to dec 1), 5w30 winter (dec 1 to jun 1). Been running this schedule since Feb2006 w/o regard to mileage. Engine now at 223kmi.
For the Rav I am thinking I will run 5w20 summer (cant find a sae20), 0w20 winter.


I didn't see the link, but it's this Gool search that pops up the article.
https://www.machinerylubrication.com/Read/30835/lubricant-film-strength

Assuming you are in AZ, as your profile implies, why the winter rating concern?

 

[EMPIRE]

Assuming you are in AZ, as your profile implies, why the winter rating concern?

Because less long chain polymers (VI's) means a better oil. Doesn't have so much to do with AZ, has to do with the actual application of the oil. Yes, they will all thin to 20 when hot. The more chameleon the oil is the less lube you have. VI's are not lubes. If the low temp is ~80F (or 70+ for 6mo) why do I need an oil that has VI's in it?

And since this outside site is popular among some here, I will link this article. VI's have pro's and con's. A 0w20 will not always be 20 when hot because the polymers do get destroyed with use. A sae20 would not have this issue, etc.
https://www.machinerylubrication.com/Read/1327/viscosity-index-improvers

 

[OilReport99]

Because less long chain polymers (VI's) means a better oil. Doesn't have so much to do with AZ, has to do with the actual application of the oil. Yes, they will all thin to 20 when hot. The more chameleon the oil is the less lube you have. VI's are not lubes. If the low temp is ~80F (or 70+ for 6mo) why do I need an oil that has VI's in it?

Then again, why not just run the oil with the less chameleon year-round?

 

[EMPIRE]

Then again, why just not run the oil with the less chameleon year-round?

You mean like a 5w20? Yes, probably will use that.

 

[OilReport99]

You mean like a 5w20? Yes, probably will use that.

Whatever floats your boat- or your stagecoach for that matter - in Arizona.

 

[kschachn]

Is it? Or does the actual oil film keep the parts from touching?

Film thickness, yes.

 

[Gene K]

When you get into Synthetic I think that you can pretty much achieve 10W30 without any VII or with very little VII content so they don't bother with packaging a straight 30 since it would pretty much be 10w30

Schaeffer's and Amsoil both I believe still both sell dual rated SAE 30 / 10w30. It's a Straight 30 (No VII) but it meets the test requirements for the 10W Winter Rating. I believe Scaeffer's is an API.

I suspect a straight SAE 20 with primarily PAO/POE Base would also meet the requirements for 5W-20. As a matter of fact I believe the first Mobil 1 5W-20 was actually a Straight SAE 20 as well.

 

[Gene K]

Not many vehicles on the road (ie none) that have oil operating temp more than about 230 in normal conditions. Even that is somewhat rare, most are 210-215 range.

12.7L Detroit Series 60 with 41 Quarts of Oil is 195F with an oil cooler on a 100F day so the difference is not as great as you might think.


The oil may act as a sump to absorb heat but without a cooler it doesn't radiate it very well.

 

[Gene K]

Your vehicle will never see 250f oil temps so it doesn't really matter.

I don't even think there any any API certified monogrades anymore anyway.

Schaeffer's sells a dual rated synthetic not available in a 20 Grade though.

I think some of the HDEO Monogrades may carry a gasoline rating.