So I have about 11 hours in my new to me plane. I always notice the sound of the engine and it is never a smooth sound. The engine does not feel rough by any means but it sounds just not smooth..it's hard to describe it. My buddy with a warrior sounds smooth as can be. He said another guy with a 180 has the same sound as my plane so we are figuring it is just the sound of the 360. It makes full power and never hiccups just sounds other than smooth. I know sounds strange but hard to describe.