I'm starting this thread rather than high jack Dr. Haas's thread. He said this in his thread:
I don't doubt for one second that the Red Line 5W-20 made his Murcielago run quieter than the Agip 5W-40, but I just want to know why?
The old way of thinking is that thicker oils always offer quieter valvetrain operation; how can a Group IV synthetic that is on the thin side of kinematic viscosity make an engine run almost silent?
What if you had two engine oils that were of the SAME kinematic viscosity, yet one of them made an engine run much quieter than the other; how would that be possible?
Quote:
Note that in any engine going to a thicker oil will in one way make it more quiet. The thicker oil on the inside surfaces will act as a better sound buffer. Going to a thinner oil can only make it more quiet by some other method. The Murcielago was delivered with OEM 5W40 Agip, the engine was very noisy. I changed to 0W30 Mobil 1 and it became more quiet. Then I changed to the 5W20 Red Line and the engine is almost silent, it is definitely soother as well.
I don't doubt for one second that the Red Line 5W-20 made his Murcielago run quieter than the Agip 5W-40, but I just want to know why?
The old way of thinking is that thicker oils always offer quieter valvetrain operation; how can a Group IV synthetic that is on the thin side of kinematic viscosity make an engine run almost silent?
What if you had two engine oils that were of the SAME kinematic viscosity, yet one of them made an engine run much quieter than the other; how would that be possible?