What brand of oil is everyone using and what interval?

[Wolfman AK907]

Hello all...I'm going to be changing my oil for the first time on the Aveo and was curious to what everyone is using? I use Mobil 1 in my Trailblazer, Motorcraft Synthetic Blend in the wifes Mountaineer and was considering using only conventional oil in the Aveo? Any comments/suggestions? I use a 5000 mile OCI in the two SUVs but am wondering if I should drop my interval to 3500 or 4000 in the Aveo since it is a high revving 4 banger.

When I bought my car I paid for fluid changes for life through my Lithia dealership for like 500 bucks. So, I figured since I bought it I just take my car in every 3 months and get all my fluids flushed and changed. They change mine with Mobil1 Full Synthetic.

[630R63]

Castrol Syntec 5w30 all year round changed every 5000 KM (3000 Miles) with a FRAM synthetic filter (aka high millage) since the second oil change.
some times it does take me more then 3 months to reach 5000 KM