First oil change questions

[HUMMERcustoms.com/TAZ]

I use AC filters but, I like WIX from all the years in farming and watching how well they performed.
It is funny Royal Purple or Redline is not on the list. My dealer asked Me if I had in mind what i wanted to use in engine, tranny, and transfer when I told Him i wanted to go all syn. this oil change and service. I told Him i was thinking of Mobile and he said good choice but, then I said I have Royal Purple in a box in the back. He sighed and said very good choice I was hoping you would go with it. I use GM syn. in diff. and eveything else Royal Purple and Service manager said change it when computer tells Me to unless in a hard and extreme use enviroment like off-roading. Computer is there for a reason other than giving you something to look at and wonder about. That is the same thing i say about non syn. He said but, with syn. i think You stay on same oil and tranny service schedule and everything is good to go. Do not extend just because You most likely could with no problem. We talked and agreed it is just a little more insurance on recommended service intervals. It may have something to do with my dealer being very performance oriented.
TAZ