High or Low Viscosity.

[Al]

A while back I would have staked my life on Higher viscosity was better. After looking at hundreds and hundreds of UOA's. I no longer feel that way. My 10K miles of 5W-40 Mobil 1 on my '22 Forester was certainly ho-hum. Going to 0W-20 Mobil 1. I expect it to do at least as well as the 5W-30 and 5W-40. I am changing today.

 

[BMW Dom]

 

[cptbarkey]

I'm not a fan of the FB engine at all in its current iteration. Also, Blackstone lied to you about fuel dilution. There is no other way around that than switch companies.

 

[wpod]

It all depends. UOAs basically tells how the oil is holding up.

 

[vpr5703]

Lets face it here - For 99% of people who drive cars on a daily basis it won't ever matter. xW-20 vs xW-30 vs xW-40 won't ever matter. And even for the 1% it probably won't matter very much. For the most part I would hazard a guess that other parts of a car die or need expensive replacement before the engine does (unless you have a Theta-ii engine. RIP Hyundai/Kia)

 

[Graham Piccinini]

 

[I<3oil]

Kewl

 

[kschachn]

2,342nd "thick vs. thin" thread with a double helping of "UOA proves one is better" fallacy.

But you forgot to add the noise factor. You would have had a trifecta then.

 

[Triple_Se7en]

A while back I would have staked my life on Higher viscosity was better. After looking at hundreds and hundreds of UOA's. I no longer feel that way. My 10K miles of 5W-40 Mobil 1 on my '22 Forester was certainly ho-hum. Going to 0W-20 Mobil 1. I expect it to do at least as well as the 5W-30 and 5W-40. I am changing today.

You ran a 10k oil for 10k?
On this new change today, is the 0w20 at least EP?
If your answers are No & No, I'd move down to a 5k OCI.

 

[DGXR]

Feelings are not facts. Use what the manufacturer recommends for your operating conditions, or at least something very close... 5w40 to 0w20 is a big change.

 

[Pablo]

I can believe a 22 year BITOG veteran started such a thread!

 

[Sequoiasoon]

I can believe a 22 year BITOG veteran started such a thread!

View attachment 210754

Can or can't?

 

[wpod]

View attachment 210751

Been using 0W-40 M 1 in everything since it first came on the market. Cept my F150 with the 2.7 engine but now M1 0W-40 is Sp Everything with a gas motor gets it. Cept if I have left over HDEO oil from my tractor then the ope gets the HDEO

 

[Pablo]

Can or can't?

Both! (just being BITOG silly, newbie would have asked.................differently)

 

[cptbarkey]

I can believe a 22 year BITOG veteran started such a thread!

View attachment 210754

Well, I am curious about all the UOA data he scraped, or if it was manual analysis over a very very long time. He had what could be contrasted as a near religious event. If I was a mod I'd give him an exception.

Will someone give away their UOA database please? Blackstone? etc? For the sake of everyone. If you are selling it, thats nice, but come on now, data should be free.

 

[Cujet]

After looking at hundreds and hundreds of UOA's. I no longer feel that way. My 10K miles of 5W-40 Mobil 1 on my '22 Forester was certainly ho-hum.

Just a reminder that UOA results DO NOT reflect engine wear rates. Not even close. In fact, no information can be gathered from normal UOA results with regard to engine longevity. I understand there is a culture of belief with regard to "wear metals" shown in UOA results.

I worked with Mobil Oil engineers on 2 projects, SHC 100 grease, and Mobil Jet 254 high thermal stability turbine engine oil. My job was to remove parts and transport them to the Mobil Oil engineers. I learned very quickly about UOA results (as we did performed them constantly. The wear rates were measured by scanning electron microscope. There was no, as in ZERO correlation.

Let's be honest about this. An Fe of 50ppm would indicate high rates of wear when contrasted to 8ppm Fe. Yet, the engine with 50 is very likely to have visible hone marks in the cylinders at 300,000 miles if maintained well. The idea that the iron comes from the cylinder walls is nonsense.

 

[ripcord]

Just a reminder that UOA results DO NOT reflect engine wear rates. Not even close. In fact, no information can be gathered from normal UOA results with regard to engine longevity. I understand there is a culture of belief with regard to "wear metals" shown in UOA results.

I worked with Mobil Oil engineers on 2 projects, SHC 100 grease, and Mobil Jet 254 high thermal stability turbine engine oil. My job was to remove parts and transport them to the Mobil Oil engineers. I learned very quickly about UOA results (as we did performed them constantly. The wear rates were measured by scanning electron microscope. There was no, as in ZERO correlation.

Let's be honest about this. An Fe of 50ppm would indicate high rates of wear when contrasted to 8ppm Fe. Yet, the engine with 50 is very likely to have visible hone marks in the cylinders at 300,000 miles if maintained well. The idea that the iron comes from the cylinder walls is nonsense.

To say it a different way, accurate wear metrics require MEASUREMENT (i.e. with dial indicators or other tools), and can't be INFERRED (UOA's).

 

[ZZman]

It really is disheartening to see all the sarcasm and negativity in some of these posts.

 

[BrendanC]

There is no reason to drop back to 0w-20…

The decrease in viscosity will NOT make a noticeable fuel economy improvement and will offer less protection than your mobil 1 5w-40.

 

[JavierH19]

You'll be crawling back to m1 5w-40 once your motor BLOWS UP





Jokes aside just make sure you check the oil level in case any accelerated consumption occurs because that could happen. That's the reason why i switched from 0w-20 to 5w-40 in my 2021 by the 14k mark. Burned a bit over a quart in the 7k olm interval which i know isn't a lot on its own but i don't care, no new engine should burn that much. With 5w-40 its barely gone down in the same mileage. Though my mpg has "gone down" it's negligible and within margin of error since it's impossible to drive the exact same but a full tank average went from 17.7-17.8 to 17.5-17.6.