OCI, not when but why?

[Homer1959]

9 hours ago, Grumpy Bear said:

 

I can find no error in your response. Sure, anything is possible. But let me run this by you. 

 

 

Referring to the red bold underlined section. That implies SOPUS knows exactly what sufficient IS and can quantify it. It also says that whatever this IS and as far down the ladder of real possibility is may lie beneath what can BE it will exceed by MORE than was it required. So....ask I ask you....what level of wear, of cleanliness of corrosion protection, of thermal properties is SUFFICIENT for you and why anyone but the end user should be allowed to determine what they DESERVE? 

 

Let me be so bold as to answer that for you. API/ILSAC/ACEA and the OEM's are telling us what is sufficient protection and yet that level they have determined as sufficient is FAILING. Not to adequately service the warranty and their margins but to provide a level of protection that benefits' the end user which other than their back account they could care less about. I know this just on a cleanliness basis by the SAE test requirements and acceptable levels of deposit formation.

 

So yes, a Group II/III blend with a robust package that will pass the SAE certifications and the OEM licensing requirements will indeed provide a level that will get the powertrain past whatever dismally low length of time and miles they warranty the product is for (their bar for Sufficient) and it will do so with a level of 'acceptable' failures that will keep the bean counters in happy land. Courts are full of oil related ring failure class action law suits. 

 

SOPUS did not error in statement. It errors in judgement and it does so willingly and at the end users expense for gain. It is a business run by the same greed as most other business. I took the same marketing classes they take. LOL. 

 

But rest assured. On base oil alone, the statement that a Group II/II+/III/III+/GTL is equivalent to or better than a PAO/POE/AN is a bold faced LIE. The statement that a well formulated Group III with and excellent add package can outperform a POA with a crap add pack is a "Strawman argument". Is it possible, yes, but...can you find me an example? I don't think so, I know so. Not in any 'recognized' brand name product. 

 

Here are a few easy examples. A Group III has a possible range of viscosity that lies between 4 and 8 cSt. GTL is even lower https://www.stle.org/files/TLTArchives/2015/11_November/Worldwide.aspx Shell sells only the 3 cSt oil to the market. So to build a *W30 some VII will be required. However blends of POA/mPOA can yield the full viscosity range without any VII for many grades and much less in the widest ranges. And it will do so with a neat VI high enough to use a fraction of the VII's. 

 

Then there is the thermal capacity and thermal transfer rates. PAO's excel in both allowing most gear boxes to run 15 F cooler. 

 

Both are non polar and require some co-base to reach an aniline point low enough to hold that 'robust' add package. For Group III's that is a Group I or Group II or both sacrificing almost all advantage the Group III's bring. OR a PAO blended with a POE or AN will yield not just a lower add pack with greater solubility but greatly enhance, by synergies, both lubricity and oxidation resistance. The addition of the Ester also dramatically enhances the film strength (HTHS) for the same grade viscosity and in nearly every case the SSI will be MUCH lower than anything one can whip up with a mineral oil derived base. 

 

Lastly a low VII product with an robust Ester or AN co-base will keep it assembly day clean for as long as you wish to run it PROVIDED a reasonable OCI. It doesn't have a 'required minimum deposit level". 

 

Now all that blather aside. I take no issue with anyone pouring Mineral based 'syn' oil into their motor and running it for whatever OEM dictated OCI's are run. Not my dog, not my fight and not my wallet. 

 

Don't be tricked by slick marketing even from the majors. I worked in Research for several Majors. They ALL lie. they don't make money by using the most expensive high performance products. They use the cheapest crap they can and tell you "It is just as good". 

 

Marketing is the business of the most profitable artful lie. 

 

 

What’s the Holy Graal for my new 2025 Sierra 2500 HD gas model then—something I can easily grab off the shelf at a big store, not from some obscure boutique? Maybe Amsoil? Or should I just use what I already have and hope for the best? I’ve got four 5-liter jugs of QS 5W-40 Euro ready to go in, and I’m not worried about the warranty since I can provide all the receipts needed to prove I’ve used Dexos-approved oil

[diyer2]

One question Homer? Do you plan on keeping this truck a long time? If so use your off the shelf oil just shorten the OCI's, 5k? If the cost doesn't bother you switch to a higher quality oil with the same OCI's.

[KARNUT]

I’ve mentioned several times over the years how Amsoil hydraulic oil has save my company thousands over the years. And how in the 80s through the early 2000s we went extended up to 25K miles with their oil. Extending hours in our ROW equipment. Did oil analysis and became a dealer. Other oils eventually caught up or at least got close. I don’t drive as much retired and don’t go extended. And I drive in town more vs highway. With the changes internally with most engines extending oil drains is not advisable for most people. I’m convinced 5K oil changes should be the maximum. I don’t use one brand anymore. Honda oil, Valvoline, GM, Mobile one and Amsoil. Who’s the best? I don’t know. If I did my own changes I would use Amsoil. All my daily drivers are plus 150K and use no oil. I know Grumpy test all the time with real world results. Can’t go wrong there. That’s my 2 cents.

[Homer1959]

On 3/24/2026 at 9:57 AM, diyer2 said:

One question Homer? Do you plan on keeping this truck a long time? If so use your off the shelf oil just shorten the OCI's, 5k? If the cost doesn't bother you switch to a higher quality oil with the same OCI's.

7 years or 60k is my goal. We use it  solely to pull our TT from quebec to texas for the annual snowbird trip. At that time ill be 73 so ill be done with camping. Ill follow the OCI and do minimum maintenance on it, no need to invest more than i have to do in this truck 

[Grumpy Bear]

On 3/24/2026 at 8:47 AM, Homer1959 said:

What’s the Holy Graal for my new 2025 Sierra 2500 HD gas model then—something I can easily grab off the shelf at a big store, not from some obscure boutique? Maybe Amsoil? Or should I just use what I already have and hope for the best? I’ve got four 5-liter jugs of QS 5W-40 Euro ready to go in, and I’m not worried about the warranty since I can provide all the receipts needed to prove I’ve used Dexos-approved oil

 

On 3/25/2026 at 10:53 AM, Homer1959 said:

7 years or 60k is my goal. We use it  solely to pull our TT from quebec to texas for the annual snowbird trip. At that time ill be 73 so ill be done with camping. Ill follow the OCI and do minimum maintenance on it, no need to invest more than i have to do in this truck 

 

Given you goal dyier2 hit it pretty much square. Use the QS 5W40 Euro and change is on a shorter schedule. Whatever your OEM recommended OCI /2. I'm going to guess that at 3,750 miles or 6K Kilometers. You want to use AMSOIL SS 0W40 go 5K and call it a day. You want to go longer? Do a few OCI's on your choice but if not then flying blind my suggestions stands.  

[Black02Silverado]

On 3/25/2026 at 11:53 AM, Homer1959 said:

7 years or 60k is my goal. We use it  solely to pull our TT from quebec to texas for the annual snowbird trip. At that time ill be 73 so ill be done with camping. Ill follow the OCI and do minimum maintenance on it, no need to invest more than i have to do in this truck 

Any off the shelf oil would be fine, especially if you are not planning on keeping it.  But one thing to look into is keeping the inside clean.  Valvoline made Restore & Protect because even with 5k oil changes the inside still carbons up, especially the rings using most off shelf oils.  Now using a higher quality oil like AMSOIL would prevent that.  Most look at UOA's but now there is a different view to oils, which keeps the inside clean and rings free? To me the extra cost is worth it.  

[Z45]

fyi  This is good.

 

https://www.autoblog.com/news/valvoline-sued-after-using-the-wrong-oil-in-customers-engine

 

[Black02Silverado]

1 hour ago, Z45 said:

fyi  This is good.

 

https://www.autoblog.com/news/valvoline-sued-after-using-the-wrong-oil-in-customers-engine

 

 

Would not have been an issue if they put the correct oil in.  General public mostly goes unaware when they go to quick lube oil changes.
 

This is why I change my own oil. 

[Z45]

Oh, I thought the consensus on these forums was 0W- oil is NO GOOD, don't use?

[PunchT37]

1 hour ago, Z45 said:

Oh, I thought the consensus on these forums was 0W- oil is NO GOOD, don't use?

I`m one of those. Unless I`m on the arctic circle, no 0w oils for me.

[KARNUT]

4 hours ago, Z45 said:

fyi  This is good.

 

https://www.autoblog.com/news/valvoline-sued-after-using-the-wrong-oil-in-customers-engine

 

I use Valvoline quick lube. They use oil from a drum. Being most vehicles use 0-20 I find it hard to believe they would use anything different unless asked. My recipe says oil specified as well as my window sticker. Most vehicles specify the weight on the filter cap. I’m skeptical to say the least.

[Grumpy Bear]

8 hours ago, Z45 said:

fyi  This is good.

 

https://www.autoblog.com/news/valvoline-sued-after-using-the-wrong-oil-in-customers-engine

 

 

I think this is going to be a big lift for the petitioner. Can't say a thing true in court and proof of claim is a much louder voice than the reality as they will find out. 

 

[Grumpy Bear]

ISO 4406 and OCI

 

Do you know what it is and does it matter? 

 

 

 

 

[diyer2]

What oil, how frequent it's changed and who does it a personal choice. I will change my oil myself with the products I like until I no longer can do it. 

No one touches my vehicles, toys or other motors unless it can't be avoided. 

[Grumpy Bear]

On 6/12/2026 at 12:38 AM, Grumpy Bear said:

ISO 4406 and OCI

Do you know what it is and does it matter? 

 

On 6/12/2026 at 10:09 AM, diyer2 said:

What oil, how frequent it's changed and who does it a personal choice. 

 

I would not argue that with you. It would be pointless to argue against the truth and you speak the truth. 

 

My question and in fact the entire point of this thread is an exploration into the levers of wear which happens no matter how well we maintain our powertrains. 

 

Some of these levers we exert a good deal of influence over which can and do result is lower wear, longer powertrain life. Some others we are sort of stuck with. 

 

An engine is typically done when the ring to bore seal no longer is able to do the job effectively. Normally the first thing to go in a engine otherwise well maintained and adult driven is this seal. 

 

Looking into the means, methods, products and attitudes that influence the rate of wear seems a worthwhile inquiry to me.