I have 4200K on my SF Sport Limited. Car was ultra quiet when running, perfect. Got my oil changed at the dealer yesterday, and nowit idles rougher, and pretty much drive like i am in ECO mode. Turbo doesnt sound as smooth. This sucks. Looked at the receipt from the dealer and it says he used Castrol 5w20 oil. My manual and the oil cap say 5w30. Could this be the cause? Any ideas.