Ok I just switched to a K&N drop in filter.. Noticed some difference. As far as fluids switch them all to Syn. I am going to Switch to Royal Purple because I can get a hook up for the stuff. Right now I have Valvoline Syn. In my Diffs and T-case, and Mobile 1 Syn. in my engine. As far as anti freeze, I don't think it really matter. For fuel injector cleaner there is something I can't remember the name I think it was BG-22, that stuff is supposed to be good. I have ran Seafoam and that stuff made a bit of a difference too. Up to you really. If you want more info do a search in the backyard mechanic section and you will find a phlethoria of info there.