I just finished installing the bypass filter and doing the first oil change. Used 10W-30 Amsoil (6 qts.) since the bypass filter holds 1 qt. Now I will do a complete oil change about every 40,000 miles. Every 3000 miles I will change the bypass filter element (toilet paper roll) and put in a new qt. of oil. So the additives remain good. I used the same bypass filter housing on two Dodge with cummins turbodiesels and two of my previous toyota tacomas. Combined mileage over 300,000 running extended drain with synthetic oil (Amsoil). Many years ago all cars were sold with oil bypass filters. This filtration will get down to under a half a micron as well as catching any entrained moisture, acids, etc. The regular filter cannot come even close to micro-polishing the oil like that.