I'm learning slowly but surely how to take care of my mustang...and i'm not too great at the whole mechanic thing YET...however i do have a question. what's the difference between a closed system breather cap and an open system breather cap? any answers would be appreciated. thanks...

 

Open system caps "breathe to the atmosphere via a "screen" type filter in the cap. Closed system breathes through a hose into either the PCV system or the air cleaner to prevent less blow-by gasses.

 

is anyone one better than the other?