LSJr tests and discusses DexosD babymax oils

[johnmyster]

Those temp. are probably close if not the same to the gasoline engines. However, the LM2/LZ0 engine is turbocharged like all modern diesels. So those are pretty normal temps.
It will be more interesting to compare oil temps. In gasoline engines the normal temp. is about 212°F.

We can cherry pick data to try and make a point but your generalization is still incorrect. The LZO/LM2 runs hot in an attempt to gain efficiency and minimize particulate production.

I'm not sure why high temperature would be harder on a 20 weight than a 40. Again, another generalization that doesn't hold water.

 

[Japanese]

I'm not sure why high temperature would be harder on a 20 weight than a 40. Again, another generalization that doesn't hold water.

Because of the higher HTHS of the 40 grade or ACEA C3 oil. Also, I'm not aware of any German V6 turbo diesel car which runs on 0W-20 oil. All of them run on ACEA C3 oils that might be either 30 or 40 grade. And also run between 8.5 and 10 qts of oil.

 

[johnmyster]

Because of the higher HTHS of the 40 grade or ACEA C3 oil. Also, I'm not aware of any German V6 turbo diesel car which runs on 0W-20 oil. All of them run on ACEA C3 oils that might be either 30 or 40 grade. And also run between 8.5 and 10 qts of oil.

I think you're confusing an oil's physical characteristics at temperature with thermal degradation. Just because an oil is a 20w at 100C (or beyond) doesn't mean it can't hold up at those temperatures.

"German v6 turbo diesel" seems like an odd measuring stick for an oil. It's like saying I'm the strongest 44 year old mechanical engineer with a size 12 shoe at my firm.

 

[kschachn]

I'm not sure why high temperature would be harder on a 20 weight than a 40. Again, another generalization that doesn't hold water.

Do you understand the physics of an oil film?

 

[DGW444]

There are a few people on here who use ESP 0W-20 in their gasoline engines. Also, I bought 3 jugs of it for a friend's hybrid SUV after reading and taking advices from the forum.
About the diesel engines—they not only run at much lower RPM but also at lower temps. as well, compared to gasoline engines.

These 3.0 Duramax engines run ~230-240°F at operating temps.

 

[DGW444]

I would like him to become a member on here and say what he has to say, instead of hiding behind his YouTube videos. It is kind of like that movie the Wizard of Oz! In that movie we had Dorothy, the Tin man, the Lion, and the Scarecrow. It is time for the Wizard to confront the Wicked Witch of the West!

That is odd, Lake uses his real professional identity and provides reasoned data to the universe. Even the most respected contributors on this forum are hidden behind their user names.

 

[johnmyster]

Do you understand the physics of an oil film?

I understand that the physical properties of oil changes with temperature and that behavior is planned/accommodated/designed/accounted for in the system. I'm not sure why that's all the sudden we're considering that "hard on" an oil.

Now if you were to say we need an HTHS of XX at YYY temperature, and a 20w oil doesn't meet that specification, I'd agree.

If you had an oil that maintained it's properties (over time) at 100C but degraded at 125C, then you'd have a point that temperature is "hard on" an oil. But that isn't related to viscosity. Not at all.

Jappaneesy is using baseless comparisons to support a sliding scale of subjective judgement calls where "hard on" is now a driving parameter for fluid specification.

 

[kschachn]

That is odd, Lake uses his real professional identity and provides reasoned data to the universe. Even the most respected contributors on this forum are hidden behind their user names.

Unfortunately he cannot grasp some rather basic science. I'd rather be technically correct than anything else.

 

[kschachn]

I understand that the physical properties of oil changes with temperature and that behavior is planned/accommodated/designed/accounted for in the system. I'm not sure why that's all the sudden we're considering that "hard on" an oil.

Now if you were to say we need an HTHS of XX at YYY temperature, and a 20w oil doesn't meet that specification, I'd agree.

If you had an oil that maintained it's properties (over time) at 100C but degraded at 125C, then you'd have a point that temperature is "hard on" an oil. But that isn't related to viscosity. Not at all.

Jappaneesy is using baseless comparisons to support a sliding scale of subjective judgement calls where "hard on" is now a driving parameter for fluid specification.

Understand though that the automaker's "planned/accommodated/designed/accounted for in the system" is based on providing acceptable wear and performance under most circumstances, in accordance with what their objective is to achieve CAFE and EPA rules. As a result it's not wholly a technical recommendation but rather one that also achieves only a minimum standard for the user.

 

[johnmyster]

Understand though that the automaker's "planned/accommodated/designed/accounted for in the system" is based on providing acceptable wear under most circumstances, in accordance with what their objective is to achieve CAFE and EPA rules. As a result it's not wholly a technical recommendation but rather one that also achieves only a minimum standard for the user.

That's not what I'm arguing. I don't disagree that any particular OEM could/would specify a different lube if wear was the only priority rather than also considering cost, fuel economy, maintenance interval, corporate alliances, and/or availability, etc. Ironically, similar choices are made in engine design where longevity/reliability isn't always the leading priority. If I had an LZO and planned to love it long time, I wouldn't use 0w-20. My beater Mazda doesn't even get it.

I'm arguing/trolling one particular post that globally asserted that a 20 weights were "challenged" at temperature in one post (without acknowledging what physical parameter would be challenging) and then in another asserted that diesel combustion gives off less heat and in another thread a bunch of nonsense about sump sizes. Generalization after generalization based on cherry picked (and often incorrect) "data" inferred from anecdotal observations.

Poorly designed engines, poorly designed lubricants, and poorly specified lubricants are three different topics that need not be confused.

I have a friend who had and really liked his LZ0 pickup. For him it was a corporate white collar commuter and hardware store errand status symbol truck. In 18 months it spent 6 months at the mechanic for emissions issues. N=1 anecdote, but oil choice and operating temperature was not even on his radar. He traded it. It covered the cost of a new Subaru Outback with all the options.