The wife and I are picking up her new vehicle on Wednesday, an 04 Envoy SLE with the 1SB package. I wanted the SLT 1SC, but didn't want to pony up the extra $100/mo. She even picked out a black one with the high polished wheels. Just what I need, another black vehicle to keep looking great. I did a search on the few threads here on the truck and am very happy to hear such great things about that engine. My question, as you would expect, revolves around the oil of choice. It looks like both Amsoil and Mobil 1 (10W-30 in both cases I think) gave excellent wear numbers. I have some Amsoil ATM sitting around along with some GC and even some S2k 0W-30. I plan on doing an oil and filter change at 1,000 miles, but don't know what to toss in there. Also, is there an oversize filter option? The wife is much more gentle on cars and engines than I am and I imagine that any of the above listed oils will be fine. I just wanted some additional insight to verify my thoughts.