I am looking for a good HDEO 5w30 preferably synthetic. I am running the amsoil 5w30 HDD and I like it but am sick of having to plan ahead for changes so I am looking for alternatives It is for a Jeep 4.0l Inline 6 and yes yadda yadda a regular oil is adequate for that flat tappet motor, I don't agree I want a HDEO. I am running the 5w-40 Rotella syn in my dodge dart Slant six I just want to stay out of a 40 weight if possible. the jeep is a daily driver and i want to keep it light ( I know how demanding of me wanting a light weight fuel efficient HDEO)