While I don’t have an oil separator and I have no plans of adding one, I dont subscribe to the theory of “ I have never seen a need for one of these. Evidently the factory doesn't either, or they would install them.”We have four (4) 3.6 engines in the family. I service and change the engine oil and air filter in all four of these. I have never seen a need for one of these. Evidently the factory doesn't either, or they would install them. But for those that disagree with this, then go ahead and spend your money..LOL