Using HDEO's in Gasoline Engines

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A friend of mine shared this post with me. I cannot agree with the author on reason(s) #1/#3 because many HDEO's are dual-rated. For Reason #4, it can be difficult to distinguish the differences between fuel dilution related shearing and actual viscosity breakdown. I am not sure on #2, but I would assume that any dual-rated HDEO would have addressed this issue. Thoughts?
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Reason 1: Primary ZDDP. What most people just call Zinc, ZDDP is an additive package in oil that is known for anti-wear properties. I'll spare you the science behind ZDDP decomposition tiers and the nature of boundary lubrication, but what you have to realize is that there are 200+ formulations of ZDDP and they are not all equal. They come in two main categories: primary and secondary. Primary ZDDP is used mostly as an antioxidant to fight oxidative thickening in engine oils in high-heat applications, of which there are plenty in diesel engines, and is also geared more for lower friction coefficient. By contrast, gasoline engines either use mostly secondary ZDDP with some primary, or exclusively secondary (which is the case of higher quality oils), and is geared more for tribofilm formulation. Basically, your 1200ppm of Zinc in Rotella T6 is not actually protecting better than 800ppm of Zinc API SN spec synthetic oil and certainly not better than a high secondary ZDDP formulated gasoline engine oil. Reason 2: Anti-foaming. Also referred to as air release, the oil has to release air pockets generated during friction and movement. Rotella is not very good at this, and that's OK when you are running a Detroit Diesel with a 2100RPM redline or even a 6.7 Powestroke with a 3400RPM redline (where the anti-foaming starts to become a bigger issue), not so much when you're running a Subaru FA20 with a 7400RPM redline. Under extended use, this can eventually aerate the fluid enough to cause catastrophic failure, or at minimum power loss. Reason 3: Detergents/Dispersants. Diesel engines typically deal more with soot handling and dispersion, so the additive package is designed accordingly. On the other hand, gasoline engine detergent packs are designed more to handle acidity. This discrepancy can also result in reduced performance in gasoline engines as the detergent tries to clean the cylinder walls, which compromises the seal between rings and cylinder walls and reduces compression and efficiency. Reason 4: The other day someone challenged me to post oil analysis reports of Rotella T6 shearing (thinning) in viscosity. I did a google image search for Rotella T6 (virgin viscosity of 14.9 cSt) and struggled to find a single oil analysis that was actually in-spect! In fact, I'd say 9/10 oil analysis reports showed that it had sheared in viscosity. If you're looking for a high quality base oil with additives that don't shear in viscosity, this isn't your best option. Now I'm sure I'll get the classic "I've been using this oil and nothing has blown up yet" rhetoric by people who are too cheap to consider better options like AMSOIL, Driven Racing, Motul, and Schaeffer, but that doesn't mean that the product doesn't have its deficiencies simply because you want it to work. I realize people have a higher tendency to believe information that they agree with regarding a cheaper product than a more expensive one, but unless you already knew everything I presented in this post, you ought to reconsider your lubricant choice in gasoline engines (especially high-revving and turbo gasoline engines). There are far better options on the market that will protect better and make more power. Feel free to share wherever appropriate.
Link to the full post (I omitted some parts in my quote): https://www.facebook.com/andrei.pop.1460/posts/10100248410515674
 
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In engines with known LSPI occurrence, I'd be worried and stick carefully with the specified oil. But for everything else, I don't see any "downside" to a HDEO other than obtaining the specified viscosity may be difficult, especially since 0W-20 HDEO's are nowhere to be found pretty much.
 
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I dont agree. 20 years ago i knew a farmer that only used Delo 15w40 in his farm truck that had 400K miles then. He drove it all over the country to horse shows. That was way before dual rated. Farm Truck was a chevy with a 350. I also know of a tow truck that has only seen Rotella 15w40, its a gasser. Guy makes a living with it doing repos and salvage tows, last i heard had nearly 500K. Also way before dual rated. 15w40 has been used in gasoline powered boats for decades as well. On T6 5w40 you could search for months on motorcycle forums, UTV, and OPE forums and probably never read of a failure...just praise. With that being said i doubt much of a difference could be found in 5w30 Valvoline conventional versus T6 5w40 in just about anything as long as the oil was changed modestly. "you ought to reconsider your lubricant choice in gasoline engines (especially high-revving and turbo gasoline engines). There are far better options on the market that will protect better and make more power." Protect better? Im guessing UOA would reflect this? Wear metals? Make more Power? never heard of an oil that made more power.
 
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just dropped the ST HD 15/40 HDEO SN ran all summer in my Lexus, no issues, replaced with M1 0/40 facing seasonal temps to possible -40F.
 
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Reason 2: Anti-foaming. Also referred to as air release, the oil has to release air pockets generated during friction and movement. Rotella is not very good at this, and that's OK when you are running a Detroit Diesel with a 2100RPM redline or even a 6.7 Powestroke with a 3400RPM redline (where the anti-foaming starts to become a bigger issue), not so much when you're running a Subaru FA20 with a 7400RPM redline. Under extended use, this can eventually aerate the fluid enough to cause catastrophic failure, or at minimum power loss.
Funny they made reference a Subaru DI engine using Rotella T6. It has been well know for at least 5-6 years that despite Rotella T6's cult following among Subaru enthusiasts that this specific oil does not function well at all in Subaru direct injection engines. Go over to NABISCO and one of the first threads you'll likely come across states this very clearly in the first post. Most people using Rotella T6 in a Subaru engine are usually doing so in a port injected WRX or STi, often with a cat deletion mod. It has a very solid track record of producing excellent results under those circumstances.
 
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Very different environments. I can see foaming being an issue at high rpms. "A diesel engine with high load, low rpm wants a high pressure-viscosity coefficient and high HTHS. They aren't as concerned with high windage, aeration, and acidic contaminants. Gas engines with less load, high rpm need to worry about foaming, aeration, and shear stability." "Rotella T4 15w-40 wouldn't last 2 laps around Daytona in a cup engine, and Driven XP2 0w-20 wouldn't last 10 miles down the highway in a Mac MP10. Different base oils, different additives, different testing parameters, etc... it's comparing apples to oranges." On a side note, aeration was a big development factor with GM when making ESP 0w40 for the new Vette.
 
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Originally Posted by buster
Very different environments. I can see foaming being an issue at high rpms. "A diesel engine with high load, low rpm wants a high pressure-viscosity coefficient and high HTHS. They aren't as concerned with high windage, aeration, and acidic contaminants. Gas engines with less load, high rpm need to worry about foaming, aeration, and shear stability." "Rotella T4 15w-40 wouldn't last 2 laps around Daytona in a cup engine, and Driven XP2 0w-20 wouldn't last 10 miles down the highway in a Mac MP10. Different base oils, different additives, different testing parameters, etc... it's comparing apples to oranges." On a side note, aeration was a big development factor with GM when making ESP 0w40 for the new Vette.
so, actually, it's probably no bueno in all those shared sump motorcycles that almost always rev much higher than a diesel.
 
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As long as the diesel oil meets the specifications called for by your vehicle, I don't think it's an issue. I don't entirely agree with the OP. I saw the OP in quotes on another forum. He seems to know quite a bit about oil, but is wrong on a few things, this being one of them.
 
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Originally Posted by buster
Very different environments. I can see foaming being an issue at high rpms. "A diesel engine with high load, low rpm wants a high pressure-viscosity coefficient and high HTHS. They aren't as concerned with high windage, aeration, and acidic contaminants. Gas engines with less load, high rpm need to worry about foaming, aeration, and shear stability." "Rotella T4 15w-40 wouldn't last 2 laps around Daytona in a cup engine, and Driven XP2 0w-20 wouldn't last 10 miles down the highway in a Mac MP10. Different base oils, different additives, different testing parameters, etc... it's comparing apples to oranges." On a side note, aeration was a big development factor with GM when making ESP 0w40 for the new Vette.
I would imagine a HDEO would be better in keeping aeration in check seeing how many HEUI-equipped Ford/Navistar and Caterpillar engines are out there.
 
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Originally Posted by NormanBuntz
The guy you quoted sounds like a shill for boutique motor oil.
This was the first thing I thought once I got to the 5th quoted paragraph in the original post.
 
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OH
Silly stuff quoted from a silly site. Too many people here have used dual rated HDEOs for there to be any serious question about their suitability to gas engines. There is also the horses for courses thing. I'd not use a dual rated 5W-40 in one of my cars for which 0W-20 is the recommended grade, but I would and have used dual rated HDEOs in my old BMW and would not hesitate to put such an oil in our old Legacy 2.2 or our old E350 351W.
 
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I firmly believe PCMO is better for typical gas engines. If HDEO was really somehow better for gas engines, then why wouldn't all the majors simply convert their production to HDEO only? Why spend all the R&D efforts and dollars to make the great PCMO's we have now?
 
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All the points can be debunked easily, though this type of troll post deserves no deep response. HDEO will work fine in engines that aren't nasty LSPI producers. Gasoline ratings such as SN mean the oil meets antifoaming and performance guidelines. If your vehicle requires "sn" or "SM" and the oil meets it...you are good to go so long as you are not experiencing cold temperatures below the oils capability.
 
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I have too many outstanding UOAs using HDEO in gasoline engines (none of them had sheared out of grade BTW) to consider any of his points valid. I would argue the HDEO UOAs probably have on average, lower wear metals vs regular SM/SN oils, the majority of which were expensive synthetics.
 
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