Is Shearing and Oxidation happening at the same time?

[Patman]

I will let the oil drain all night to get most of the oil out. My driveway is not flat so that helps.

View attachment 278802

Even doing that you will still have at least a half a quart of oil left behind in the oil passages and cylinder heads.

 

[kschachn]

This is what I got from Blackstone ago

View attachment 278553

Blackstone is incapable of distinguishing whether a viscosity deviation is due to mechanical shear of the VM or fuel dilution.

 

[Motor oil rookie]

Even doing that you will still have at least a half a quart of oil left behind in the oil passages and cylinder heads.

But how come I got full 5 quarts out last time?

 

[kschachn]

At 40 degrees, the difference is not measurable. I bet someone has somewhere some measurements, but this is how it is measured:
https://www.selectsynthetics.com/part-2--oil-viscosity-grades-.html#:~:text=By this time, the SAE,heat and high load situations.

https://blog.amsoil.com/understanding-oil-viscosity/

This appears to sometimes be a very difficult thing to understand.

 

[Motor oil rookie]

This appears to sometimes be a very difficult thing to understand.

I opened that link and it went over my head

 

[Motor oil rookie]

This person on Reddit made me nervous about 5W-30. So I will use a 0W-20 that doesn't shear and thickens a little bit.

 

[kschachn]

I opened that link and it went over my head

Winter ratings are for cold weather performance and don’t predict performance at warmer temperatures. The behavior of an oil with a 0W winter rating vs. one with a 5W rating is only predictable below about -30 or so.

 

[kschachn]

This person on Reddit made me nervous about 5W-30. So I will use a 0W-20 that doesn't shear and thickens a little bit.
View attachment 278811

Have you conclusively determined that you have a problem with mechanical shear of the VM in a particular oil? Most engines do not have this issue

 

[Motor oil rookie]

Have you conclusively determined that you have a problem with mechanical shear of the VM in a particular oil? Most engines do not have this issue

I don't know yet.

 

[kschachn]

I don't know yet.

It’s probably unlikely. Many people on here worry a great deal about shear when most viscosity deviations are due to fuel dilution. The causes is different and so are any possible mitigation.

 

[Motor oil rookie]

Have you conclusively determined that you have a problem with mechanical shear of the VM in a particular oil? Most engines do not have this issue

Did you see a poster here just uploaded his Red Line 0W-20 UOA? His Honda Accord chewed that oil from 9.0 to 8.2. My Jeep will chew it even more. I think this HPL Super Car will be better for me.

 

[OVERKILL]

I am running Red Line 0W-20 now. I will change my oil in November. When I use this HP over Red Line, can a negative reaction happen? Thank you

No, you'll be fine.

 

[kschachn]

Did you see a poster here just uploaded his Red Line 0W-20 UOA? His Honda Accord chewed that oil from 9.0 to 8.2. My Jeep will chew it even more. I think this HPL Super Car will be better for me.

That would be unlikely given that specific oil. What lab performed this analysis?

 

[Motor oil rookie]

That would be unlikely given that specific oil. What lab performed this analysis?

Post in thread 'Red Line 0W-20 5k mi; '17 Accord Sport 59.8k mi'

May 11, 2025

I am running this same oil in my heavily modified Wrangler that sees very high temps crawling up mountain trails in the summer heat. Your Honda sheared it to 8.28 from 9.0. I am a little nervous now. Does your Accord show oil temp?

No oil temp gauge, just the coolant temp.

• Devo242

• 

 

[OVERKILL]

Post in thread 'Red Line 0W-20 5k mi; '17 Accord Sport 59.8k mi'

May 11, 2025

I am running this same oil in my heavily modified Wrangler that sees very high temps crawling up mountain trails in the summer heat. Your Honda sheared it to 8.28 from 9.0. I am a little nervous now. Does your Accord show oil temp?

No oil temp gauge, just the coolant temp.

• Devo242

• 

Without a VOA from Blackstone, I wouldn't bet the farm. They are often WAY off on viscosity (and don't measure fuel directly, which is another issue).

Look at the differences in viscosity between Blackstone and OAI/Polaris in this thread:

Thread 'Mobil 1 0W/40FS European Car Formula 2.7k mi; 2002 Ford Ranger 3.0L Vulcan 111.8k mi'

May 1, 2025

Not much to report, obviously it sat a lot.

• DuckRyder
• Replies: 9
• Forum: Used Oil Analysis - Gasoline

• 

 

[Patman]

But how come I got full 5 quarts out last time?

Because the engine had 5.5 quarts or more in there when you started draining it. It’s impossible to get 100% of all of the oil out of your engine via the drain plug.

 

[Motor oil rookie]

Without a VOA from Blackstone, I wouldn't bet the farm. They are often WAY off on viscosity (and don't measure fuel directly, which is another issue).

Look at the differences in viscosity between Blackstone and OAI/Polaris in this thread:

Thread 'Mobil 1 0W/40FS European Car Formula 2.7k mi; 2002 Ford Ranger 3.0L Vulcan 111.8k mi'

May 1, 2025

Not much to report, obviously it sat a lot.

• DuckRyder
• Replies: 9
• Forum: Used Oil Analysis - Gasoline

• 

In my case they showed 9.0. In the comments I said I want to test whether is really 9.0 or not. Maybe they took my money and lied.

 

[Motor oil rookie]

Because the engine had 5.5 quarts or more in there when you started draining it. It’s impossible to get 100% of all of the oil out of your engine via the drain plug.

Does that mean next time I should pour 4.5 quarts only?

 

[OVERKILL]

In my case they showed 9.0. In the comments I said I want to test whether is really 9.0 or not. Maybe they took my money and lied.

View attachment 278812

Yep, sometimes they are on, sometimes they are off, lol.

 

[Motor oil rookie]

Yep, sometimes they are on, sometimes they are off, lol.

Or maybe one shouldn't reveal any information to them at all. Just tell them test this oil. They seem to have a huge database and numbers are already there, they just do copy and paste. I have my doubts now. If you send them Mobil1 0W-40 but put Castrol 0W-20 in the form, they will say your Castrol 0W-20 looks good. So hard to trust people.