What oil/oils have made your engine more quiet?

[ChiTDI]

GC made the engine quieter than the 5w30 Mobil 1 I was running in a V6 Toyota.
Different viscosity though.

 

[Bruce T]

Overk1ll, multiple oil changes and then a UOA was only performed on the Red Line 5W30 at 5K miles. The results were good but not great, but I intentionally tested it during the worst case time of the year (dead of winter). The Valvoline SynPower has had some good UOAs on BITOG, but I never was willing to run a Group III past 3K in this engine. It might have worked with LC20, but I don't know about that.

Yes, people like to rag on Mobil 1, since they're big and popular. Most people outside of BITOG haven't heard of Amsoil, Redline, GC, etc. Ha, I suppose everyone likes to fantasize that they alone possess hidden knowledge of the dark oil arts.

 

[Mau]

going from M1 5w30 to PP 5w30, I found pp made my engine sound quieter and smoother (4cyl turbo motor)

 

[HTSS_TR]

M1 0W40 to PP 5W20 in E430 makes engine quieter, even my wife thinks the engine is quieter because the oil is platinum. Gas mileage is improved about 1 MPG, from around 18 MPG to 19 MPG after 2000 miles of mostly city driving.