I want to say that the 3.6 still is hard on the oil. Only true way to tell is to pull a sample out at 5k after you have some miles on it and go from there.
Ours was hard on the oil more so because we do a lot of stop and go short trips, like less than 5 miles one way short trips. It saw highway but not enough to off set the bad short trips.
You can get a sample kit from AMSOIL for $27 from Oil Analyzers. Prepaid mail. Just fill bottle, fill out form, and put it in the mail.
Yeah, I think I will do the sample on the 2nd change. I have learned not to pull samples on the factory fill...it's scary!
I found 6 quarts of OE 5w30 I had left over from the Tahoe...I may give in, and just switch it over. I just want to use up my freebies. Dealer said they will put in Mobil One on both oil changed for an extra 30 bones.