Lake Speed Jr. ... Diesel vs Gas oils

That is why it's always better to do some research, and try to get some knowledge before blindly accepting a recommendation. There may be many possibilities for what is being discussed in the video.

For instant: in my old Opel Kadett, which is recommended 15W40 / 20W50, i use HDEO CI-4/E7 instead of a PCMO. My choice is not only for the ZDDP, but for the reasons below:

1. My car runs on ethanol (100%), so the higher TBN and oxidation control of the HDEO could be a benefit for me.

2. 15W40 are often the cheaper oils around here, mainly because they are cheap to produce having only API SL approval. So a HDEO 15W40 ACEA E7 and all the MB 228.3, Volvo, Cummins and etc... approvals may indicate a greater challenge to overcome, resulting in a better product. This can also mean the PCMO 15W40 can get by with Grp I while the HDEO must use Grp II to meet the required standard.

That being said, i can get, for the same money, a 5W40 PCMO with Porsche A40 approval. Should i use that, even if the recommendation is 15W40/20W50 and i live in a tropical country? Will the oil pressure be the same since the HTHS of the 15W40 is greater than the 5W40? I always ask my self that question, and the reality is: it would be really hard to measure the difference or benefit.

Going back to the video, yes, we can all agree that the AW additives can compete with detergents. But the oil formulation didn't think this through, adding the right amount of AW to overcome this? I guess diesels engines also requires a good amount of AW, since they suffer the same challenges of metal to metal contact, and achieve millions of miles. And what about dual rated oils?
 
Wonder how the Brotella fans are going to take this?
The Brotella fans are going to say that if HDEOs increase wear in a gasoline fueled engine, they will also increase wear in a Diesel engine.
The purpose of the video is to discourage people from using value priced Diesel engine oils even if they are API CK-4/SP approved instead of over priced “classic”, racing, marine and motorcycle oil.
If the AW ZDDP competes with the detergent package for surface and increases wear, explain how an old school generation one 350 small block Chev running on LPG will go a million miles on HDEO 10w30.
 
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DO NOT watch a Doug DeMuro video. 🫣
I met him at a Cars & Coffee one time. He seemed cool in person. I find him insufferable in his videos. #ShrugLife

Just going to toss a wrench in here…
Years ago, Castrol was big at touting that Calcium and Sodium detergent compounds had BOTH detergent/dispersant functions, but ALSO had strong anti-wear attributes as well. They put a lot of Ca in GTX as part of this finding.
Old-school HDEO still do tend to have a fair amount of Ca detergent in them, so isn’t this wear issue mitigated a lot? Isn’t he exaggerating the ‘dangers’ a bit?
I'm sure that's one of many nuances he left out. I think it's safe to say he was simplifying to make a point.

And what about dual rated oils?
Outside the scope of the video.
 
I'm guessing the lack of fm in rotella contributed to it having the worst cam wear figure or no it just performed poorly for some other reason?
It's the detergent/dispersant vs Zinc ratio (they compete w/each other that causes wear). HDEO needs to have more of that detergent to help w/soot... necessary evil if you will. Sorry if I'm misunderstanding your question. It's not the FM that's the problem.
 
As I commented in the video comments nothing about those results were conclusive other than really didn't make a difference. The 40wt HDEO vs the 50wt could have made those minuscule differences (0.09 vs 0.11 for the Valvoline VR vs DELO) in wear. I use 30wt diesel oil which doesn't have all the anti-wear zinc/phosphorus and are often CK4 and SN rated.
 
If I were running a GDI engine I'd probably heed his advice, as that's what he seemed to be aiming it at.
However, my old clunker VW is indirect injection and my bikes are all carburetted, and the Mannol Extreme
5w40 I've got 40 litres of will do all of them just great.
I've been running a couple of them on it for the past few years and have no signs of distress so far. However, my bike transmissions chew any oil up by 2000 miles, so I always have the benefit of a fresh fill long before the oil is worn out in engine terms. The Mannol is JASO MA rated.
For the old VW clunker, it will be happy with the Mannol, but I'll run that longer - up to 5K miles.
So, basically his vid is informative, but I see no reason to change my choice.
 
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What he said in well known in the tribology field. Here is one paper discussing the effects of detergents and dispersants on ZDDP’s antiwear role. https://www.researchgate.net/public...e_Tribofilm_Composition_and_Boundary_Friction

Article showing the evolution of dispersant chemistries:
https://www.infineuminsight.com/en-gb/articles/the-art-of-dispersant-design/?search-referral=true

In the hotter environments of diesel engines, deposit formation on the different parts of the engine caused by high temperature degradation of the oil can lead to engine failure. This could be reflected in ring sticking or an increase in blow-by. The dispersant must solubilise or wash away the polar entities formed before they coke or form deposits that adhere to the surfaces and interfere with engine function. It is critical that the hydrophobic to hydrophilic ratio of the dispersant is high enough to avoid the dispersant being pulled out of solution by the polar entities, since this would actually form deposits rather than preventing them.

In diesel engines, it is preferable to avoid the use of a large number of high molecular weight polymers since they can form coke forming carbon deposits in the engine. Instead, dispersants that are large enough to keep contaminants in solution but small enough to wash down the piston surfaces are selected.
 
Maybe, but that doesn’t explain the thousands of motorcycles and outboard boat engines running fine and dandy on $4 HDEOs.

I think the video is an infomercial disguised as science.
Most motorcycles have a much lower OCI. At least mine do, so it probably does matter as much. Especially with a wet clutch, the oil gets full of clutch material anyway
 
So whats the consensus on oil to use in old engines equipped with flat tappets? Traditionally HEDO, like Rotella 10W30, was recommended by many on this forum.
 
That is why it's always better to do some research, and try to get some knowledge before blindly accepting a recommendation. There may be many possibilities for what is being discussed in the video.

For instant: in my old Opel Kadett, which is recommended 15W40 / 20W50, i use HDEO CI-4/E7 instead of a PCMO. My choice is not only for the ZDDP, but for the reasons below:

1. My car runs on ethanol (100%), so the higher TBN and oxidation control of the HDEO could be a benefit for me.

2. 15W40 are often the cheaper oils around here, mainly because they are cheap to produce having only API SL approval. So a HDEO 15W40 ACEA E7 and all the MB 228.3, Volvo, Cummins and etc... approvals may indicate a greater challenge to overcome, resulting in a better product. This can also mean the PCMO 15W40 can get by with Grp I while the HDEO must use Grp II to meet the required standard.

That being said, i can get, for the same money, a 5W40 PCMO with Porsche A40 approval. Should i use that, even if the recommendation is 15W40/20W50 and i live in a tropical country? Will the oil pressure be the same since the HTHS of the 15W40 is greater than the 5W40? I always ask my self that question, and the reality is: it would be really hard to measure the difference or benefit.

Going back to the video, yes, we can all agree that the AW additives can compete with detergents. But the oil formulation didn't think this through, adding the right amount of AW to overcome this? I guess diesels engines also requires a good amount of AW, since they suffer the same challenges of metal to metal contact, and achieve millions of miles. And what about dual rated oils?

The HDMO's detergent chemistry won't help with ethanol dilution. What you need there is something to prevent the ethanol from becoming a catalyst for transesterification and depolymerization. This is why ethanol is detrimental to ZDDP, being an ester. You also want a higher (and better) anti-oxidant concentration to prevent ethanol (and the water it carries with it) from breaking hydrocarbon bonds.

That said... if the engine is frequently at full operating temperature above ethanol's boiling point (174°F / 79°C), the threat and effect of ethanol dilution is greatly diminished. Thus, you're unlikely to have a problem from the ethanol that you wouldn't have otherwise, and cookie cutter API detergent and anti-oxidant chemistry will do just fine. The move to an HDMO though is a side-step, not a step forward, in the battle. It's not providing any benefit either way but likely not harming anything either.
 
So is the lure of these oils for those that use them in gas applications the words "heavy duty" and the bigger viscosity numbers 15, 40, etc.?
Also, AFAIR...

1. The perception that they are more heavily additized (more = better amirite)

2. Some early threads in which people got better UOA results with HDEOs that were cheaper per volume than high-end synthetics. IIRC those HDEOs were actually dual-rated, but when people saw "HDEO" they projected the results onto Diesel engine oils.

At this point the myth has taken on a life of its own.
 
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