Engine sounds and drives way better after oil change

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Originally Posted by DrDanger


P.S. If oil did not make any difference, what are we doing here
smile.gif




Does one really "pick" their illness? :p
 
I've found some oils to be quieter than others, Castrol Magnetic, Rotella Gas Truck. Now maybe that's in my head, but it sure seems real to me. I also notice a slight uptick in fuel economy with almost any oil I use, for the first 500-700 miles or so.
 
Keep in mind that antiwear additives take several hundred miles to begin functioning optimally. Until a used oil is loaded with contaminants or depleted it protects against wear better than new oil.
 
Fresh oil raises compression. I've proven it several time in a shop setting. May only be 5-10 psi, but it does nonetheless. Sometimes two oil changes in a row will raise it more.

We tested compression on a couple cars when the Valvoline traveling salesmen came around hocking Valvoline "engine flush". It was a gallon of pure synthetic oil with lots of detergents. It came in a gallon and was crystal clear. You dump the oil and filter, run a new filter and this oil in the parking lot for 15-30 minutes, then change the oil again with the oil and filter that will be in service for the interval. The Valvoline guy claimed his flush/cleaning product raised compression, and I proved to him while he was standing there on a similar car that two subsequent oil changes could (and will) raise compression by a perceptible amount. They actually ran the cleaner product on my personal car, and I ran two oil changes in a row on a customer car that was in for an oil change. So that particular customer got a "flush" gratis, with Synpower and didn't even know. Compression raised on both cars nearly 20 psi across all cylinders.

This is why your car feels better after an oil and filter change.
 
just to confirm because it may be confusing but i either had castrol edge 5w30 or penzoil ultra platinum/platinum 5w30 in it before, i cant remember which one exactly because it was prob what was on sale.

the new oil that the dealership said they put in was 5w30 full synthetic dexos gen 2

i asked the wife as well and she drove the truck today (3 days) after oil change and even she noticed the difference, she agrees it does sound better and it feels smooth idk why


so i guess it just attributes to the new oil being a little thinner or thicker? and there was no way that the castrol edge/pp 5w30 that was in it before was going bad? (it only had like 5k km on it max) as in needed to be changed?
because the place i get it changed sometimes puts the 8000k sticker or the 5000k sticker but all i know is that i changed it out 3000km before it was actually due
 
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Has anyone actually done a 'blind' study to determine whether there's really any difference after an oil change?

I (out of sheer boredom) watched a YouTube series put on by an Amsoil dealer ("Synthetic Oil Protection"), and he's always claiming a quieter engine after Amsoil, but its pretty clear that he's comparing a cold engine, to a warm engine noise-wise. Using such to 'promote' the oil he deals.
 
Originally Posted by TiGeo
placebo

Exactly, same after washing your car, seems to run great.
cheers3.gif
 
Originally Posted by pitzel
Has anyone actually done a 'blind' study to determine whether there's really any difference after an oil change?


Not that I'm aware of and it's why these posts are so funny to me. Wouldn't science be so much easier if we could just do simple observations, correlate those with "what makes sense" to us and call it a day?

These observations are meaningless except to the person experiencing the dilution who is, of course, absolutely convinced their observation is real.
 
Originally Posted by Malo83
Originally Posted by TiGeo
placebo

Exactly, same after washing your car, seems to run great.
cheers3.gif


so true omg it seems to run so much smoother,
one time with my cts i detailed the car with the most expensive products available,in a Ferrari dealer ship it cost me like 1000$,put new set of Michelin pilot mxv4,new m1 oil,new transmission oil. I swear I was high for weeks.i drove with the radio off for days just socking the perfection,
it was spiritual I tell you.
and then the check engine light came on...
 
You can't deny the placebo effect but if you change engine oil long enough with different cars and/or different oils, you'll observe that some engines sound "smoother" with certain oil/type/grade.
 
Originally Posted by Malo83
Originally Posted by TiGeo
placebo

Exactly, same after washing your car, seems to run great.
cheers3.gif


There you go...
 
Switched from Motorcraft 5w-20 to Castro's Edge 5w-20 EP.

Noticeably quieter. Even my wife noticed without prompting.

Just a little bit thicker, I expect. Perhaps the difference is no more the sheer on the old oil vs. the new.

It wouldn't stop me from using one oil over another. Might be something to keep in mind at trade-in time.
 
Since this subject comes up pretty frequently here I thought I would provide some evidence. This is still not scientific but it's a step up from just "earsay".

I just changed my oil in the Mazda. The engine was warmed up. I used a decibel reading app in my iPhone to see what difference if any there was between old and new oil. I had the phone in the same spot for each reading.

With the old oil the average reading was 74.4 decibels. The new oil average reading was 73.8 decibels.

Now, did the engine sound quieter to me? I will say yes but the decibel readings are not significantly that far apart to make a difference. My guess is that it's a difference tone or frequency of noise.

So based on all this, there is no difference.
 
Off topic, but not really. Decibel measurements are not linear. In fact the difference in intensity you described is significant.
However perceived noise is highly individual and is subject to the wavelength of the noise. Decibels measures sound pressure and the intensity based on a logarithm ." On the decibel scale, the smallest audible sound (near total silence) is 0 dB. A sound 10 times more powerful is 10 dB. A sound 100 times more powerful than near total silence is 20 dB. A sound 1,000 times more powerful than near total silence is 30 dB"

https://science.howstuffworks.com/question124.htm

I do noise surveys and personal dosimetry as part of my profession.
Noise is highly misunderstood.



Originally Posted by PimTac
Since this subject comes up pretty frequently here I thought I would provide some evidence. This is still not scientific but it's a step up from just "earsay".

I just changed my oil in the Mazda. The engine was warmed up. I used a decibel reading app in my iPhone to see what difference if any there was between old and new oil. I had the phone in the same spot for each reading.

With the old oil the average reading was 74.4 decibels. The new oil average reading was 73.8 decibels.

Now, did the engine sound quieter to me? I will say yes but the decibel readings are not significantly that far apart to make a difference. My guess is that it's a difference tone or frequency of noise.

So based on all this, there is no difference.
 
Originally Posted by Bryanccfshr

Off topic, but not really. Decibel measurements are not linear. In fact the difference in intensity you described is significant.
However perceived noise is highly individual and is subject to the wavelength of the noise. Decibels measures sound pressure and the intensity based on a logarithm ." On the decibel scale, the smallest audible sound (near total silence) is 0 dB. A sound 10 times more powerful is 10 dB. A sound 100 times more powerful than near total silence is 20 dB. A sound 1,000 times more powerful than near total silence is 30 dB"

https://science.howstuffworks.com/question124.htm

I do noise surveys and personal dosimetry as part of my profession.
Noise is highly misunderstood.



Originally Posted by PimTac
Since this subject comes up pretty frequently here I thought I would provide some evidence. This is still not scientific but it's a step up from just "earsay".

I just changed my oil in the Mazda. The engine was warmed up. I used a decibel reading app in my iPhone to see what difference if any there was between old and new oil. I had the phone in the same spot for each reading.

With the old oil the average reading was 74.4 decibels. The new oil average reading was 73.8 decibels.

Now, did the engine sound quieter to me? I will say yes but the decibel readings are not significantly that far apart to make a difference. My guess is that it's a difference tone or frequency of noise.

So based on all this, there is no difference.





Interesting stuff. Thanks for linking that. It also doesn't help that I am deaf in one ear and probably not 100% in the other.
 
Jeff… does your Tesla sound quieter right after you charge it … ?
 
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