Thicker is better in my opinion.

[LotI]

Mazda SkyActiv in he US calls for 20 grade oils in the non-turbo applications but up to 50 grades elsewhere in the world.

My GM LTG engine calls for 5w-30 in the US but anywhere from 20 to 40 internationally. Thanks to AZ for the gift of RGT which is one of the thickest 30's

10w-xx oils are even on the list if they're dexos quality.

I ran 30's in my Mazda and 2 Honda K24's without a change in fuel consumption.

I consider myself a thickie but one grade up is my limit. I did run 0w-20 in my Trailblazer once, no change in any way...the engine didn't even blow up!

In the rust belt we don't worry about the engine lasting forever.

 

[JLTD]

Originally Posted by OVERKILL
Originally Posted by RDY4WAR
This is highly application specific. I've seen this tested in an engine on a dyno with grades from 0w-20 to SAE 50. There was a slight decrease in wear going to 5w-30, but it stayed the same with each grade above that. All the higher viscosity oils did was cause more parasitic drag / power loss.

Much of your "normal" wear is coming from areas that operate in mixed and boundary lubrication regimes with the exception of the rod and main bearings. The additive package is far more important than the base oil and viscosity.

Nailed it.


+1; WAAAY engine specific. Have to agree that thicker is better in the 3.5EB.

 

[CR94]

Originally Posted by tcp71
... An increased oci is really the only way to remove those particles.
Not likely! Increasing the interval between changes will only allow the concentration of those evil particles to become higher.

 

[Bryanccfshr]

Originally Posted by CR94
Originally Posted by tcp71
... An increased oci is really the only way to remove those particles.
Not likely! Increasing the interval between changes will only allow the concentration of those evil particles to become higher.


Although not well phrased I understood CR94 to mean more frequent OCI and not longer OCI,

 

[SR5]

Originally Posted by aquariuscsm
I've always been a "thickie".


Same here, and possibly a bit thicker than you.

Hope your doing well Aquariuscsm

 

[aquariuscsm]

Originally Posted by SR5
Originally Posted by aquariuscsm
I've always been a "thickie".


Same here, and possibly a bit thicker than you.

Hope your doing well Aquariuscsm


Thank you SR5! I hope you're doing well too my brother

 

[tig1]

Originally Posted by JLTD
Originally Posted by OVERKILL
Originally Posted by RDY4WAR
This is highly application specific. I've seen this tested in an engine on a dyno with grades from 0w-20 to SAE 50. There was a slight decrease in wear going to 5w-30, but it stayed the same with each grade above that. All the higher viscosity oils did was cause more parasitic drag / power loss.

Much of your "normal" wear is coming from areas that operate in mixed and boundary lubrication regimes with the exception of the rod and main bearings. The additive package is far more important than the base oil and viscosity.

Nailed it.


+1; WAAAY engine specific. Have to agree that thicker is better in the 3.5EB.

Yes, best to stick with oil cap advise.

 

[SR5]

Originally Posted by tig1
Originally Posted by JLTD
Originally Posted by OVERKILL
Originally Posted by RDY4WAR
This is highly application specific. I've seen this tested in an engine on a dyno with grades from 0w-20 to SAE 50. There was a slight decrease in wear going to 5w-30, but it stayed the same with each grade above that. All the higher viscosity oils did was cause more parasitic drag / power loss.

Much of your "normal" wear is coming from areas that operate in mixed and boundary lubrication regimes with the exception of the rod and main bearings. The additive package is far more important than the base oil and viscosity.

Nailed it.


+1; WAAAY engine specific. Have to agree that thicker is better in the 3.5EB.

Yes, best to stick with oil cap advise.


Nice post RDY4WAR,
Within cold start requirements, most engines should be quite tolerant of oil viscosity. The biggest viscosity swing they see is due to temperature, not oil grade.

M1 0W20 Viscosity = 44.8 cSt (at 40 degrees C)
GTX 15W40 Viscosity = 14.5 cSt (at 100 degrees C)

Here is the owners manual from Australia for a 2018 Camry Hybrid, it says you can use 0W16, 0W20, 5W20, 5W30, 10W30 or 15W40

https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/4890579/1

BTW our oil fill caps just say "oil" or show an oil can.

 

[dave1251]

Originally Posted by RDY4WAR
This is highly application specific. I've seen this tested in an engine on a dyno with grades from 0w-20 to SAE 50. There was a slight decrease in wear going to 5w-30, but it stayed the same with each grade above that. All the higher viscosity oils did was cause more parasitic drag / power loss.

Much of your "normal" wear is coming from areas that operate in mixed and boundary lubrication regimes with the exception of the rod and main bearings. The additive package is far more important than the base oil and viscosity.



There was a SAE study to confirm this. There are a few out of every thousand engines which are going to fail prematurely and every engine will fail if driven long enough. Fooling around with grades makes some folks feel like they have control and this is what satisfies them. This is okay IMO there are worse things to fret about.

The OP titled this thread perfectly in he stated it's his opinion. After starting a few threads about this very same topic about using 40 grade in his "new" engine he got this one right.

 

[CR94]

Originally Posted by RDY4WAR
This is highly application specific. I've seen this tested in an engine on a dyno with grades from 0w-20 to SAE 50. There was a slight decrease in wear going to 5w-30, but it stayed the same with each grade above that. All the higher viscosity oils did was cause more parasitic drag / power loss. ...
What minimum grade was the engine under test designed to use? Was the sump temperature maintained at levels typical of everyday use?

 

[mpack88]

My 18 Taurus seems to like 0w20 RGT. It had ST syn 5w30 and was averaging 21mpg. Now its getting 27 mph. It's now in its third oil change so maybe it's just now broken but the 0w20 seems to be the winner for me. Its smoother feeling as well.

 

[RDY4WAR]

Originally Posted by SR5

Nice post RDY4WAR,
Within cold start requirements, most engines should be quite tolerant of oil viscosity. The biggest viscosity swing they see is due to temperature, not oil grade.

M1 0W20 Viscosity = 44.8 cSt (at 40 degrees C)
GTX 15W40 Viscosity = 14.5 cSt (at 100 degrees C)

Here is the owners manual from Australia for a 2018 Camry Hybrid, it says you can use 0W16, 0W20, 5W20, 5W30, 10W30 or 15W40

https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/4890579/1

BTW our oil fill caps just say "oil" or show an oil can.


An important factor to consider is bearing heat. As known, higher viscosity generates more hydrodynamic friction. Imagine two bowls, one filled with water and the other with honey, and try to stir them both with a spoon. The honey is much harder to stir due to the increased friction from the higher viscosity. This is a somewhat similar concept to crank journals spinning around in high viscosity oil. A result of friction is heat. That 0w-20 oil at 40*C and ~45 cSt could produce a temperature delta through the bearings up to 80*C rise. That 15w-40 oil at 100*C and ~14.5 cSt may only produce a 10-30*C temperature delta through the bearings. While the 0w-20 is much more viscous at 40*C than the 15w-40 at 100*C, the inlet temperature is much lower to where a higher amount of friction and temperature rise can be tolerated without overheating the bearings and wiping the bearings. Put in an oil that's ~45 cSt @ 100*C sump with an 80*C temp delta, then you might have a problem.

 

[OilUzer]

Originally Posted by mpack88
My 18 Taurus seems to like 0w20 RGT. It had ST syn 5w30 and was averaging 21mpg. Now its getting 27 mph. It's now in its third oil change so maybe it's just now broken but the 0w20 seems to be the winner for me. Its smoother feeling as well.


21 to 27 mpg! Most definitely other factors (e.g. break-in?) involved besides the oil (30 to 20). I don't think any oil can do that.

 

[Navi]

I will admit it is application specific...like do you need specialized oil a Toyota Camry 4 cylinder or Hybrid? I dont think so. Toyota really knows how to make long lasting 4 cylinders. However, Im dead set on not using those 0W16 or 0W20/5W20 oils even in a Toyota. Maybe I should have titled the thread differently admitting my dislike for the 16 and 20 oils. Unless you have a reason to use another weight I think for the Toyota Hybrid stick with 5W30.

For these Ecoboost turbos and Subaru turbos I would only use 5w40.

As far as XW16 or Xw20...nope! That Costco 5W30 deal seems ideal for Camry owners...

 

[dblshock]

I still have 4 qts of older 5/20 on the shelf, use it as bar oil when the saw is needed.

 

[Whammo]

I'm the opposite. Every time I try 5w30 in my Optima after using the recommended 5w20 everything feels more sluggish and less smooth. If you change your oil ever 3-4k, 5w20 is not going to cause harm.

 

[RazorsEdge]

Originally Posted by demarpaint
Originally Posted by Farnsworth
Originally Posted by demarpaint
Originally Posted by Farnsworth
Add one or two cans of STP, or "Motor Honey" to support the knowledge learned.

Nope. To keep it real real simple: If your engine is making metal to metal noise with a 20 grade move up to a 30 grade, if if makes noise with a 30 grade move up to a 40 grade, that's what I get from this.

Sometimes something as simple as bumping up a grade can resolve consumption and engine noise with no further action.

It was a joke.

I hear ya. The frequency of these threads are becoming a joke lately. Same story different wording..........


Quite frankly the forums are becoming the same topics, day in, day out!

 

[Silk]

Yeah, but the thin oil types just love a prodding. Always a big response if you trash thin oils, not so much if you trash thick oils.

 

[dblshock]

when my new '03 2.4 Accord started burning 5/20 @60k I let go...it's no darn good for highway miles especially.

 

[SR5]

Originally Posted by RDY4WAR
Originally Posted by SR5

Nice post RDY4WAR,
Within cold start requirements, most engines should be quite tolerant of oil viscosity. The biggest viscosity swing they see is due to temperature, not oil grade.

M1 0W20 Viscosity = 44.8 cSt (at 40 degrees C)
GTX 15W40 Viscosity = 14.5 cSt (at 100 degrees C)

Here is the owners manual from Australia for a 2018 Camry Hybrid, it says you can use 0W16, 0W20, 5W20, 5W30, 10W30 or 15W40

https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/4890579/1

BTW our oil fill caps just say "oil" or show an oil can.


An important factor to consider is bearing heat. As known, higher viscosity generates more hydrodynamic friction. Imagine two bowls, one filled with water and the other with honey, and try to stir them both with a spoon. The honey is much harder to stir due to the increased friction from the higher viscosity. This is a somewhat similar concept to crank journals spinning around in high viscosity oil. A result of friction is heat. That 0w-20 oil at 40*C and ~45 cSt could produce a temperature delta through the bearings up to 80*C rise. That 15w-40 oil at 100*C and ~14.5 cSt may only produce a 10-30*C temperature delta through the bearings. While the 0w-20 is much more viscous at 40*C than the 15w-40 at 100*C, the inlet temperature is much lower to where a higher amount of friction and temperature rise can be tolerated without overheating the bearings and wiping the bearings. Put in an oil that's ~45 cSt @ 100*C sump with an 80*C temp delta, then you might have a problem.


Yeah put an oil in that is 45 cSt at 100C, and I suspect your problem will be getting it up to 100C from a cold start. Even Penrite 40-70 (called 40W70, but no real 40W cold starting standard) has a 100C viscosity of 31 cSt and a 40C viscosity of 325 cSt. I'm of the belief that the biggest problem is starting (cranking and pumping), if you can start with an oil and let it warm up gently, then you will be ok.

Sure friction will makes a thick oil run a touch warmer, but it will work and still be thicker than a thin oil running a touch cooler. But you know all this, you are an expert, my comments were more for clarification for readers new to the field.

And that, "use what is on the cap" doesn't apply to much of the world, and I think undersells the ability of an intelligent owner to read a temperature viscosity chart to use an oil suitable for their climate and application.