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! What was the temperature of the oil when you took the first reading, and the second reading? I wonder if that would impact anything?
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! What was the temperature of the oil when you took the first reading, and the second reading? I wonder if that would impact anything?