i use royal purple 5w30 full synthetic w/ kn filter i can feel the different smooth

 

well so far my feeling with the 10w-40 ...

i can feel the engine maybe a little slower on the revving since of the higher weight... but it seems that it broke in a little.
as far as noises. my eng is always quiet n smooth so no big diff there.

i think i will try to find RP next time.