Study on Engine Noise Level vs Oil Formulation

[1978elcamino]

In my F150 w/5.0 the engine makes less noise with mobil 1 truck and suv oil than regular mobil 1. Formulation has something to do with it for sure.

 

[SR5]

We now have two papers, which cover ten cars and multiple different oils. The average measurement, for the difference in sound level, from the paper Shannow found is 4dB.

Sure not all cars and oils show a change in sound level, but some do.

The papers show the effect is real, measurable, perceptible and reproducible.

So what’s the issue now? Oh that’s right, it’s forgettable.....

 

[ZeeOSix]

Some people don't even believe repeated scientific results. Kind of like flat earthers keep believing the Earth is flat, even though science has proven it's not. 😂

 

[SR5]

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.

Sure, but the 3dB rule is made for a noisy work place like a factory or a mine site. From the link given above they say:

“.... a worker exposed to a continuous sound intensity level of 83dB(A) for one hour would be exposed to the same amount as someone exposed to an 80dB(A) level for two hours.”

 

[BLND1]

Edit: Willful ignorance is a powerful thing.

 

[Jetronic]

My car is a 2.0 diesel. Buddy at work bought the same but with a 1.6 diesel (same block but different bore/stroke). People usually say the 1.6 is more refined and I suppose with less rotational and reciprocating mass it could very well be but....

Bud at work got a ride in mine and commented that the engine is noticeably quieter... Noiw if you research the oil I use (it's in my sig), you will find other people commented that the oil made their engines quieter aswell. Coincidence? maybe. But a fun fact that he said it's quieter, I didn't mention anything...

 

[SR5]

shannows “paper” is a single grainy table referencing obviously dated oil weights with zero methodology or treatment information. Further, it literally omits nearly HALF of its follow up data.

The second paper is specifically testing an experimental oil with novel properties and it even references little to no dB variation amongst off the shelf oils, even of differing weights.

I’m not going to expend any further energy trying to explain (again) why your statement on “real, measurable, Perceptible, and reproducible“ is completely incorrect. It’s a poor appeal to authority and fallacious on its face (in addition to being completely wrong). If you choose to remain ignorant of fundamental testing principles and statistical analysis that’s your business.

Please show me your papers that show the effect does not exist.

 

[BLND1]

Please show me your papers that show the effect does not exist.

I’m still waiting for yours that show the effect does exist.

What we have is an impass - you wish to ignore any sound scientific explanation regarding the subject and I no longer care to bother to explain.

Have a nice day.

 

[SR5]

I’m still waiting for yours that show the effect does exist.

What we have is an impass - you wish to ignore any sound scientific explanation regarding the subject and I no longer care to bother to explain.

Have a nice day.

But we have two (or one if you prefer) publications that show the effect is measurable because they give actual dB measurements that show a change. This means it does exist.

 

[4WD]

In my F150 w/5.0 the engine makes less noise with mobil 1 truck and suv oil than regular mobil 1. Formulation has something to do with it for sure.

We need a DOHC with long chains formula ! My pushrod V8 is the quietest engine I have …
all the rest form the chain gang …

 

[ZeeOSix]

Edit: Willful ignorance is a powerful thing.

So you really believe that no engine on earth can have a different sound level dependent on what oil is used in it?

 

[bbhero]

The human ear (healthy) can sense a 1dB change and 3 dB change is usually fairly apparent. The problem of course with anyone saying they can “tell the difference” is that there simply isn’t a direct reference. You aren’t hearing oil x and then an immediate comparison to oil y. Beyond that - ambient noises can change drastically as well - as sources as innocuous as a garage door opening down the street or a car driving a street over can affect the receptors perception of sound. Using this report - a change between 20 and 30 wt oils gave approximately 1dB of change. Oils of similar weights likely have LESS difference. So we are talking about the very bottom end of what humans can discern and then NOT talking about every other variable in our uncontrolled garage or driveway or whatever.

Simply put - you aren’t hearing a difference between oils. You can’t control the ambient sounds and you don’t have a direct comparison. If there is a difference it likely isn’t discernible by the human ear. And certainly not discernible (at best) 20-30 minutes later in a completely uncontrolled scenario (assuming an oil change).

I’m tired of this nonsense.
Edit: if you’ve actually ever taken noise readings you will know that they aren’t a static number - they have lots of variability. Beyond that, even the distance between you and the source (by as little as a foot) can affect your perceived noise level. Not to mention the hundred other things that can skew noise levels or your perception of them. If a certain oil makes you FEEL better then use it - but trying to stretch this study into some sort of cudgel for your superhuman ears argument is asinine.

Disagree with you on this my friend...

One would have to be literally deaf as Helen Keller not to have noticed the difference between Cam2 and Super Super S 5w30 mix which only had 1,400 miles on it and what I put in after that which was the Federated Auto parts 5w30 semi synthetic oil.

It was serious difference... As soon as the Federated made it to the top of the motor in that Camry... Way quieter.

 

[wemay]

Until using QSUD and QSGB a few times, i never 'thought' there was a sound difference. Royal Purple has also been one of the quietest oils i've used.

 

[bbhero]

This is like saying... A stethoscope is just like any other stethoscope.

Not true.

Cheapy stethoscopes are no where near as good as a very good one.

The difference is in the materials in the stethoscope. Especially the tubing... The Littman cardiology II has one tube that is very flexible. A cheapy Littman had hard rubber in the tube section.

And... A Littman 3200 that is electronically aided... Like mine... Is even way better than the Littman cardiology II... Every time I hand my scope to a coworker they were amazed at how much better they heard and what they heard with my stethoscope. Like night and day difference many of them told me.

I had a Littman cardiology II which was $205 when I bought it. It was very good. Many physicians had the same stethoscope.

My Littman 3200.... Was $320 on sale... Regular price was $360. Worth every dollar spent.

 

[OilReport99]

Some people don't even believe repeated scientific results. Kind of like flat earthers keep believing the Earth is flat, even though science has proven it's not. 😂

The earth ain’t flat, but you can square the circle with the proper oil viscosity.

 

[RamFan]

Until using QSUD and QSGB a few times, i never 'thought' there was a sound difference. Royal Purple has also been one of the quietest oils i've used.

Funny you reference QSUD. I used to have a 1500 w/ the 4.7l, I never noticed a difference in engine noise with the exception of when I used QSUD. The formulation at the time ('10-'12) made a noticeable difference in engine noise.

 

[Greasymechtech]

Redline 5w30 was one of the quietest oils in my timing chain non-balance shaft equipped iron block/aluminum head DOHC 4 cyl engine. It was very obvious when compared to the store bought oils... Probably a combination of the HTHS and moly, when compared to M1/SOPUS/BP oils.

Now I user thicker than required oils to avoid psychological tinnitus

 

[RTexasF]

Funny that this oil vs engine noise came up. I have run my '08 RAV4 V-6 on 5W30 Amalie for the last 3 years since that's what the shop I use has. The engine has always had a tiny bit of start up noise for just a second or two. I'm tuned to my car so I hear it, others might not.

After the last oil & filter change the cold start was quiet, notably quiet. Was I losing it? Nope, further cold starts were the same. The new owners of the shop had changed to Chevron Supreme which they put in my car. I don't know if it's the synth blend or not but will find out when the weather & roads clear up here. The price was the same as dino Amalie, no upcharge. This proved to me without a doubt that a different oil can make an audible difference. Prior to this I always thought that was pure crappola. I was wrong.

Adding to my previous post:

After the RAV sitting for more than a week of below freezing temps and some below 0º F a genuine cold start made nary a tick or a click. I even left the driver's door open to hear the start up clearly. This has to be the Chevron Supreme that is a synth blend. I'm glad the shop I use made the change.

 

[SteveG4]

Thought this was somewhat interesting, especially the engine noise level vs oil formulation used data. We've all seen various threads where people say they can hear an engine noise level difference with different oils, and some say it's "all in their head" or "their ears aren't sensitive enough to tell a difference". Guess I go with science on this one.

https://iopscience.iop.org/article/10.1088/1757-899X/493/1/012008/pdf

Fantastic find. It's not in our collective heads then.


From the opening section, Effects of Lubricant Quality on Engine Performance:

1.3 Effects of lubricant on the engine noise
When the engine changes in a large working condition, the moving parts inside the engine will be
subjected to a large vibration shock. The buffering action of the lubricating oil will absorb a part of the
impact and reduce the vibration of the parts. At the same time, under the oil lubrication, the vibration
generated during the engine friction is reduced, thereby the mechanical noise of the engine is reduced
[5].Under the cooling effect of the lubricating oil, the lubricating oil assists the engine to dissipate heat,
and avoids the knocking due to the excessive temperature of the engine, thereby reducing the combustion
noise of the engine. At present, the average indoor noise of small cars is about 65dB, and the average
value of medium-sized cars is about 61.63dB [4]. Engine vibration will affect the service life of the
engine, and the noise will affect the comfort of the vehicle. If the engine can reduce vibration and noise
through the oil, it will improve the service life of engine and comfort inside the car [6-7].


And from section six, the Conclusion:

Combining the data obtained in Table 6 and Table 7 with the formula 3-6, it can be seen that the
developed lubricating oil has certain effects and advantages on energy saving, emission reduction and
noise reduction of the engine, and also has practicality and versatility.

 

[Silver]

I can understand some doubt when someone says "I changed my oil and it's a lot quieter". Well, that can be the case for any new oil, even the same exact kind.

But, if you go from a used 'quiet' oil to a new 'loud' oil, then you're probably onto something. I just thought of something - maybe a new oil can be louder because it's washed the old tribofilm away and not established its own? I guess you'd have to change back to the quieter oil in say 1,000 miles to see if it had quietened down after it laid its own film down.