The Blackstone viscosity range is incorrect, your oil sheared to a 20 weight.

https://www.bobistheoilguy.com/viscosity-charts/

I run 0W-40 at the moment as well, minimum 3.5 HTHS for greater oil film thickness at the bearings.:)

Kind of a late reply to your specific post, but this seems to have something to do with something other than the viscosity of your oil. I just got my oil tested after a 10,000 mile run, and most of my numbers are WAY lower than yours, despite having gone for more than twice as long between oil changes. My engine only has 7,000 less overall miles than yours too...

And I'm using boring ol' 0W-20 oil.

https://scontent-ort2-2.xx.fbcdn.net...f8&oe=5C531D7E

*Check the Y-axes before you make conclusions for the 3 different graphs, the starting X-axes are different*

**25°C = 77°F**

If you look at the viscosity charts the only significant difference between 0W20, 0W30, 5W30, 0W40 is the cold starts.
And "cold" meaning ≤30°C (≤86°F) comparing 50 cSt with 0W20 vs ~100 cSt (0W30, 5W30, 0W40).

So if you live in snowing regions, absolutely 0W20.

https://i.imgur.com/p2XPsFZ.png




If you live in places that is consistently ≥37°C (≥100°F) then switching to 0W30, 5W30, 0W40 would be a smart move IF you push your car hard

https://i.imgur.com/4kCoW4x.png



If you push your car seriously hard for long periods of time (Track), then 0W40 would be your best protection even at 120°C (248°F).

https://i.imgur.com/3FbxP0N.png



PS: M1 = mobil 1; Zepro = Idemitsu Zepro (I picked this oil because that's what I like to use as it has the lowest cSt at 40°C of 0W20 oils, other 0W20 oils are rated at ~45 cSt, - yes this widens the gap but the lesson is the same in the end)

Something to give these cSt values to things everyone is familiar with in.
Source: http://www.cstsales.com/viscosity.html

https://i.imgur.com/36cjcTI.png

Does the PDS support that statement? Because 0W should otherwise flow easier at low temps than 5W, not withstanding the effect of additives used to extend range of viscosity ratings...


EDIT - just saw the PDS numbers, and I'm surprised...looks like I might want to go to 5W-30 for the winter...I was trying to avoid using different weights depending on season, out of sheer laziness, but it seems I can't do that....

If it gets -10°F in your area, you should stick with 0W20. See charts above.

These graphs are a little puzzling to me and don't agree with anything else I've ever seen. Any 0w-whatever should flow about the same as any other 0w-whatever at zero degrees. That is what the first number means, it is the cold viscosity.

Feel free to check the actual PDS provided by manufacturers.

Edit - so I got bored and thought I would investigate how SAE300 labels oils.
https://www.widman.biz/English/Tables/J300.html
https://www.widman.biz/English/Table...sity-table.jpg

So to have a 0W title, it must pump with ≤60,000 cP at -40°C.

So what is Mobil1 0W40 MRV at -40ºC (ASTM D4684)? 21600 cP (check, it meets the ≤60,000 cP requirement)

So what about Idemitsu Zepro 0W20 MRV at -40°C (ASTN D4684)? 11,700 cP.

Both oils are rating 0W, but Mobil1 0W40 need 84.6% more force to move the same amount as Idemitsu Zepro 0W20!

It's too bad Mobil1 doesn't share their CCS. I really would like to know the cold crank centipoise.



So blah blah, what's this all mean?

Yes, mobil1 0W40 provides the sufficient protection in cold temps to get the 0W ranking, but can you get better protection for your engine? Yes. Get oil that needs less force for cold crank, cold pump, and cold flow!

You get to decide what oil you want to use, I'm just sharing what I find because I find this an interesting topic. :party0030:

PS - The chart shows why 0W and 5W are so close at the cold temp, the ranking is practically the same!

Unfortunately that info is only sporadically available, and is many times presented in differing formats even from the same manufacturer, making comparisons difficult for us tribology plebes...lol






THAT is the info I'm looking for right there - thanks! And it's kind of disappointing that SAE would allow such a broad range of performance for a given (and important) rating...

Anecdotal but, I changed to the Toyota 0W20 for the first time last week and while the air temp has only been in the mid 30's (F) the car is starting more smoothly than it used to. In the past I've used either Mobil1 that the dealer uses when they change the oil or Castrol Edge when I change it. I've also noticed that it's smoother and quieter above 4k rpm with the air temp in the mid 50's (F). These obs are about as accurate as a butt dyno but I like to think that I'm fairly well in tune with my car so...

FWIW I was very surprised that the Toyota oil was ~$6/qt including sales tax (9.something%) so depending on how it holds up I'll most likely continue using it rather than the Edge that I've been liking for a while now.

Actually, do you have the numbers for Mobil1 0w-20 as well? I'd prefer to stay within a given brand so the additive packages are most similar...

Yup, Toyota Geniune Motor Oil viscosity at 40°C and 100°C is practically the same as the Zepro 0W20 - I just use Zepro because It was cheaper at the time and comes in 5 quart jugs - I hate using the mini ones.

I've had to change the way I drive because I found myself shifting later than what I was used to because the engine was so much smoother and quiet lol

Give them a try and see how you like them.
https://www.amazon.com/ZEPRO-3001009.../dp/B072QY9GYG

https://mobiloil.com/en/motor-oils/m...-economy#0W-20

Scroll down for the details. It's pretty interesting to see the cold pump force needed to be lower than I anticipated at 9200 cP -40°C but it doesn't flow as well as the zepro 0W20 in plain gravity.


I think you're forgetting that this oil weight scale was developed in the 90's .. oil technology has moved on and improved significantly

I meant more that there is a problem with your sample data. One 0w that has half the viscosity of the others, and a 5w that has lower viscosity than a 0w, point to bad data. And that can lead to bad conclusions for a noob reading this thread. There will certainly be a range between brands, but nothing like those graphs show.


No 5w oil is going to have better cold start performance than a 0w oil even though they may be close.



I also wonder how they are going to start labeling oil once they push the cold viscosity below zero??? Negative viscosity hurts my brain.

I have no "sample data", the values are the official values provided by their respective manufacturers.

You may also be misunderstanding the ranking of the first value (0W). It is not a measure of how much volume flows for a set distance * time. It is the necessary force (cP) that must be applied to the oil in order for the oil to move a set distance * time. This is important because it shows that the oil pump is capable of pushing the oil up and begin the lubrication process when cold, but it does not able to display how well the oil natively flows overs all the internal parts (as shown in cSt - which is what the set of 3 graphs show).

So look at back the at the SAE chart and you'll see that the simple requirement to be 0W weight is to have ≤60k centipoise at -40°C at the pump and ≤6,200 cP at -35°C cold crank simulator.

The difference between that and 5W isn't too far off: pump force ≤60,000 cP at -35°C and ≤6,600 cP at -30°C.

Seeing as how 0W is a newer weight, I wouldn't be surprised if 5W was relatively close to this requirement and manufacturers had to do minimal adjustments to meet the 0W requirements. :iono:

And the centipoise and centistokes are not identical, they don't necessarily increase and decrease in a 1:1 ratio - which is why there seems to be some confusion as to the cSt chart vs cP winter oil weights.