I thought this was a very good article by the inventor of Auto-Rx and just wanted to share it with you. Oil can't lubricate through dirt.etc so you have drag/friction. Oil additives just the same. Clean metal allows any oil to lubricate every nook & cranny. Now you have no drag/friction so engine needs less gas to perform its tasks. A clean engine takes the load off the converter, Engine benefits by using less gas to perform its tasks. Please go to www.auto-rx.com and type in emissions on home page web site search engine. Read results. Auto-Rx works on mutual trust and if youre not satisfied with results your money refunded. Thats our guarantee. Frank Miller