@Chris@FreedomMotorsports, thanks for the input. I think I'm going to go with Amsoil Signature based on my oil results trend and driving conditions. I figure I might as well jump up to a higher quality base stock along with additive package if I'm going to change at all. Plus, once I'm outside of the powertrain warranty I'm going to do extended drains backed by UOA and I'd definitely use Signature for that. If I switch now, then no need to flush the engine when I start extending my change interval. Probably would never go 25k miles, but I'm sure 10-15k should be doable depending on how my UOA's look.