HPL SAE 40 PCMO

You really think that you can detect a somewhat higher viscosity oil at operating temperature?
I'm a human and feel. Robots and machines detect. :)

I don’t just think it—I feel it pretty clearly. And I'm not the only one. There are a few people here on the forum that call their engine sluggish when driven with higher viscosity. Most recent is a person in the HDMO forum that watched a video where a guy explains how his truck feels better with 10W-30 vs 5W-40. Another instance was in one of the 0W-20 where a person said that his engine feels sluggish when he switched to 5W-30.

Why would you think that is hard to feel it? People drive different vehicles. In lighter vehicles with short gears (especially manual) the physics are felt much easier than a 3-4 ton SUV or truck with automatic transmission. Usually people who know their cars well can sense (detect) any difference in their car behavior, including noises, vibrations, acceleration, etc.
 
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Why would you think is hard to feel it? People drive different vehicles. In lighter vehicles with short gears (especially manual) the physics are felt much easier than a 3-4 ton SUV or truck with automatic transmission. Usually people who know their cars well can sense (detect) any difference in their car behavior, including noises, vibrations, acceleration, etc.
Because of the truly small difference between a -30 and a -40 grade at operating temperature. I used a -40 grade at times in my old ECHO with a 1.5L manual and no way I could feel "pretty clearly" that it wasn't a -30 grade.

But hey, if you can, you can.
 
Why would you think is hard to feel it?
Because it's not blinded. You know the viscosity of the oil. The placebo effect is very strong, working in up to 20-40%. Hypnosis works for a reason. People are suggestible. I'm not saying that you don't feel something. But what you're "feeling" isn't really there, or is so small it's imperceptible to a human.
 
Because it's not blinded. You know the viscosity of the oil. The placebo effect is very strong, working in up to 20-40%. Hypnosis works for a reason. People are suggestible. I'm not saying that you don't feel something. But what you're "feeling" isn't really there, or is so small it's imperceptible to a human.
We had a former member here who swore that his engines always ran much smoother and quieter when he mixed two different oils together 🙄
 
And I'm not the only one. There are a few people here on the forum that call their engine sluggish when driven with higher viscosity. Most recent is a person in the HDMO forum that watched a video where a guy explains how his truck feels better with 10W-30 vs 5W-40. Another instance was in one of the 0W-20 where a person said that his engine feels sluggish when he switched to 5W-30.
But the original premise (ref post 277) was a mono-grade 40 would cause more HP loss than a multi-grade xW-40 at full operating temperature. How could that be when all 40 grade oils have a small difference in the KV100 and HTHS viscosity. Sure, if a much thicker oil was ran in a low HP engine someone might be able to sense some kind of perceived difference in the "peppiness" of the engine. Fire up the engine with cold oil at 10F on a dyno, do a dyno pull. Then get the oil to 200F and do a dyno pull and you will see a HP output difference. But do the same dyno test with different 40 grade oils at 200F and the measured HP difference will be in the noise of the dyno curves.
 
But the original premise (ref post 277) was a mono-grade 40 would cause more HP loss than a multi-grade xW-40 at full operating temperature.
I was commenting on the difference b/w lower and higher viscosities and that you can easily feel it when driving. Not on the difference between mono-grade and multi-grade 40 oils.
 
I'm a human and feel. Robots and machines detect. :)

I don’t just think it—I feel it pretty clearly. And I'm not the only one. There are a few people here on the forum that call their engine sluggish when driven with higher viscosity. Most recent is a person in the HDMO forum that watched a video where a guy explains how his truck feels better with 10W-30 vs 5W-40. Another instance was in one of the 0W-20 where a person said that his engine feels sluggish when he switched to 5W-30.

Why would you think that is hard to feel it? People drive different vehicles. In lighter vehicles with short gears (especially manual) the physics are felt much easier than a 3-4 ton SUV or truck with automatic transmission. Usually people who know their cars well can sense (detect) any difference in their car behavior, including noises, vibrations, acceleration, etc.

Can you feel a difference in your engine, with the same oil at 32C (warm summer day) vs 105C (engine warmed up)? If not, then you definitely can't tell the difference b/n viscosity grades.
 
I was commenting on the difference b/w lower and higher viscosities and that you can easily feel it when driving. Not on the difference between mono-grade and multi-grade 40 oils.
Got that ... but you were responding to a comment about HP loss with a mono-grade, so context didn't seem clear.

I think the detriment of higher viscosity is higher on the torque than is on the HP or at least is felt more easily, especially on cars with manual, and especially in the city. From my experience.
BTW ... HP and T are directly connected through the HP equation, so a decrease or rise in torque of say 5% also results in a HP decrease or rise of 5%.
 
Can you feel a difference in your engine, with the same oil at 32C (warm summer day) vs 105C (engine warmed up)? If not, then you definitely can't tell the difference b/n viscosity grades.
I can feel the hesitant acceleration with higher viscosity oil (5W30 vs 0W-20) when the engine is at operating temp. And as I said, other people can feel it too and say their engine feels sluggish.
 
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Got that ... but you were responding to a comment about HP loss with a mono-grade, so context didn't seem clear.


BTW ... HP and T are directly connected through the HP equation, so a decrease or rise in torque of say 5% also results in a HP decrease or rise of 5%.
For sure both are affected. I was trying to say that you can feel the torque much easier and at lower RPM than the HP.
 
I found the graph I was looking for. I found in our archives a technical report documenting the oil pressure delay of the 5.9L and 6.7L engines at -14F with regular 15w-40 Premium Blue. It also compared it to testing at -26F with 5w-40 synthetic.

The oil pressure delay was no less than 40 seconds! Now, this was circa 2008 (right after 6.7L introduction) and both the 5.9 and 6.7L had similar oil pressure delay results.

Interestingly, the delay at -10F with conventional Premium Blue in 15w-40 was nearly identical to the delay at -26F with 5w-40 synthetic (presumably Premium Blue Extreme in CI-4+ formula).

This test data aligns pretty well with the "W" ratings since 15w is tested at -25C MRV (our -10F data is -23.3C). And the -26F data is -32.2C.

So the 5w-40 and 15w-40 had nearly identical (and long) oil pressure delays when tested at their "w" rating MRV temps.

Also, keep in mind that these test points would be approximately 10C warmer than the pour points for the respective formulations.
Reminds me of this (old) video on extreme cold starts. Your cold starts with straight 40 grade isn't even close to this, but what you've described above it pretty much in line with this video. But makes the point that using the correct W rating of any oil for a very cold start-up is critical to ensure proper cold start lubrication.

 
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For sure both are affected. I was trying to say that you can feel the torque much easier and at lower RPM than the HP.
Technically, you are feeling both. Someone could say they are "feeling" torque or someone could say they "feel" HP, and both are correct because both are happening at the same time since they are directly connected through the HP equation: HP = (T x RPM)/5252.

The reason you can feel it (T and HP) more at lower RPM is because most engines typically have a steeper T and HP curve in the lower RPM range when at WOT. In the upper engine RPM range, the T and HP start flattening out and even rolling over on some engines. If you're not at WOT, then any comparison wouldn't be accurate because any throttle opening less than WOT is a variable.
 
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I can answer this one at least. He wants higher viscosity. HTHS tops out at 3.6 on that line. Good for a racing oil, but if you wanted a racing oil, then just buy their racing oil. The Euro oils top out at 4. He is looking for 4.2 minimum HTHS. That's basically where wear hits the asymptote of little to no wear occurring per Leslie Rudnick's writings. He likes the PCMO line due to the value and it checking all the boxes he's looking for.

For certain his is also looking for maximum wear protection. If I was looking for a used car I'd like to find his because I know he protected it well.
 
For certain his is also looking for maximum wear protection. If I was looking for a used car I'd like to find his because I know he protected it well.
Same. I've said before I'd be so thrilled to buy a car from a BITOG member. Most people, you are lucky if they took it to Jiffy Lube on time and paid the extra for synthetic bulk.
 
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