So i have a 2002 chevy tahoe 5.3 v8 with 255000 miles and i am trying to decide what to use for my next oil change. Here is some history. I used M1 0w-40 European spec with a M1-206a oil filter with the thought that a thicker oil may quiet my noisy gm lifters(not my idea). So not only did it not help but it was the loudest it has ever been during my ownership. Also the oil consumption was terrible. In 5488 miles it consumed over 5 qt of oil. So i went back to my standard M1 5w-30 (i believe it was extended performance) with an M1-206a filter and the lifters were much quieter but also the oil consumption dropped to 3 qt in 4968 miles and was about the same for the next oil change. Which was 5215 miles on the same M1 5w-30 extended performance and M1-206a. During that last oci i read on here that the gm small block lifters do not like restrictive oil filters or thick oil so this time i used M1 5w-30 high mileage with the larger ac delco oil filter i cant remember the number at the moment but they seem to be free flowing and my lifters are the quietest they have been since i have owned it. So i have been trying to decide if i should try M1 5w-20 this oci or stay with 5w-30? Also what filter should i use? Should i go with 5w-20 with a better filter or stick with my ac delco filters? My goal is to drive this rig until a million miles or i wreck it. Also i am interested in other oil recommendations although i am pretty stuck on M1 if you have another brand and/or grade recommendation i would appreciate reasoning based on facts and theory not experience. Cost is not a big factor in my decision i would eaven be open to trying something like redline. I just want to hear everyone's ideas and logic before i decide.