The Billet Tech Catch Can slows down and filters oil that may end up in the intake and combustion chambers. Oil in the combustion chamber could lower octane ratings that may cause your automobiles computer to sense knock/KR. This may cause a decrease in performance. The Billet Technology Catch Can helps decrease the symptoms of the scenarios described. So as you can see, the Billet Tech Catch Can not only looks good as stated, but performs flawlessly.