Study on Engine Noise Level vs Oil Formulation

When you say that did you put the Pennzoil in and immediately drain it to change to the Rotella? If you didn't then you were comparing fresh oil against old oil, which is always different. I struggle with the notion that someone's quantitative aural memory is good for 8000 miles or whatever your OCI happened to be.

Even then I question whether the real difference isn't between cold oil and warm.

No, it would take 1000 to 1500 miles. But if I had been subjected to a blind test, I would have gotten it right 100% of the time. It was that apparent. UOA's were excellent with both by the way, I've never thought it had anything to do with wear.
 
It’s because people categorically state that they can remember sound tone variations after hundreds or thousands of miles of engine operation. That’s quite a feat if you think about it, I know I can’t.

Not really so much about hearing as it is about being able to quantify your memory.
 
it is the same with our ears. Major decibel changes would be easy to tell even over long time frames “this car is much quieter than the rock concert last month.” Something as little as 1dB? Not a chance.
The study wasn't using human ears, so there's a big difference there and not comparable to what Joe vs Tom can hear or not. Some people can hear better than others, and can detect small changes in sound like sensors designed to measure sound can.
 
The study wasn't using human ears, so there's a big difference there and not comparable to what Joe vs Tom can hear or not. Some people can hear better than others, and can detect small changes in sound like sensors designed to measure sound can.

Anyone using that study to support an argument that humans can audibly and reliably detect, isolate, and then ascribe exceptionally minor changes in noise levels to a particular oil (and not one of hundreds of other variables) is engaging in fudd science.
 
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Anyone using that study to support an argument that humans can audibly and reliably detect, isolate, and then ascribe exceptionally minor changes in noise levels to a particular oil (and not one of hundreds of other variables) is engaging in fudd science.

I’m not going to bang my head against a rock to pull folks out of the dark ages.
I never said (nor anyone else) that every human can hear a difference that's actually takeing place ... but some humans can certainly hear better than others. The test showed there was a noise level difference ... it wasn't proving if every human on Earth could sense what the measurement equipment detected.
 
These guys need to hire a good marketing firm and start making some serious dough. This stuff will sell like COVID vax (at least for a while) whether it works or not.
 
Here is the paper Shannow posted previously, it gives sound levels readings in different cars with different oils mostly 10W30s but also a few monogrades. It then changes the oil in the cars to a 10W40 and then measures again after 15 minutes and again after 1week.

Depending on the car, the original oil and the time frame, the difference can be anything from 0dB to 11dB.

I bet those people driving the cars that dropped 10 or 11dB noticed a difference, and they would be correct.

Ref Thread: https://bobistheoilguy.com/forums/t...ter-switching-oil-brands.277303/#post-4535107

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It’s because people categorically state that they can remember sound tone variations after hundreds or thousands of miles ....

Not really so much about hearing as it is about being able to quantify your memory.
So we are allowed to remember what something looked like but not what something sounds like ?
 
So we are allowed to remember what something looked like but not what something sounds like ?
Does your optometrist wait 30 minutes in between their “better 1 or better 2, better 3 or better 4” Schtick? No. Why do you think it is that when making incredibly subtle changes with your sight they need to have direct comparisons in very close sequences?

Now think about 1dB differences in sound over a BEST case 20 minutes of an oil change (we’ll ignore the fact that you’ve fundamentally altered the test vessel conditions by simply doing an oil change and also ignore the other hundred or more uncontrolled variables).

It’s all in your head.
 
When an oil change allegedly results in reduced noise level, is that because the new stuff is more viscous, slipperier, has a higher damping coefficient, or is filled to a higher level in the pan than the old oil was? Or psychosomatic, because someone feels the engine should be happier on fresh oil?
 
based on major experiments, engines running oils with old style moly (not tri-nuclear) sound much smoother!
 
Just reading a few web pages on the subjective effect of changes in sound pressure level.

Change of 1 dB = Insignificant
Change of 3 dB = Perceptible, represents a doubling or halving of sound energy
Change of 5 dB = clearly noticeable
Change of 10 dB = perceived as twice or half as loud

A increase of 10 dB is perceived as twice as loud, but the actual sound energy is increased by a factor or 10, because decibel scale is a logarithmic scale.

In noise level safety they use the 3 dB rule, if the noise level increases by 3 dB then you need to half the exposure time to have the same worker exposure.

Ref:
 
Read it again - they specifically designed a lubricant that results in reduced fuel consumption by 10%! And only reduced noise by 5dB. Off the shelf lubricants of similar viscosity aren’t going to result in such drastic reductions. This also completely ignores the other inherent issues with the completely qualitative “human ear” assessment.
Your optometrist doesn’t wait twenty or more minutes in between whether “one or two” is better and then another another 30 minutes between “3 and 4” because your body simply isn’t able to differentiate that minor of a difference over that time period. A major change, sure.

it is the same with our ears. Major decibel changes would be easy to tell even over long time frames “this car is much quieter than the rock concert last month.” Something as little as 1dB? Not a chance.

And this STILL doesn’t address the uncontrolled variables.
Laughable.
Yabut....not laughable.

I agree that human memory of a sound MAY not last over 8000 miles. I say MAY because some people can recall things others will not.

However - there are Youtube videos have been done with a dB meter on the engine, showing sound differences between just-changed new oils. Off the shelf oils.

Don't take my word for it though. Have a look for yourself.
 
Just reading a few web pages on the subjective effect of changes in sound pressure level.

Change of 1 dB = Insignificant
Change of 3 dB = Perceptible, represents a doubling or halving of sound energy
Change of 5 dB = clearly noticeable
Change of 10 dB = perceived as twice or half as loud

A increase of 10 dB is perceived as twice as loud, but the actual sound energy is increased by a factor or 10, because decibel scale is a logarithmic scale.

In noise level safety they use the 3 dB rule, if the noise level increases by 3 dB then you need to half the exposure time to have the same worker exposure.

Ref:


Humans might sense the difference more depending on the source. A car engine will be hard to measure with any background noise that is usually present. However if those same decibel reductions are applied to something like a air conditioner or other appliances then it could be more noticeable since they are indoors.
 
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