Something that rhymes with CornPub . <| sep |> youta 15 . I play everyday . Please add me <| sep |> They already found the cause of the hemi tick , it was caused by the cup that the valve spring sits in . When engine valve move its too close and starts to wear , after wearing for 1520 k miles the spring moves around and rubs on the inside of the spring cup . Using 93 octane wont help for this . Also , this is no longer an issue in new 5 . 7 L ' s since they added more clearance between the cup and the spring . Not to mention the manual suggests using 89 . Why wouldnt i go with what the manual suggests ? higher is not better , there are tons of articles and studies that show that as long as your engine isnt knocking , using a higher octane fuel will not benefit you . The car is designed for 89 , so put in 89 .