On NA car, any good quality oil of using correct weight is fine. Checking to make sure your oil is at full on a regular basis (like every gas fill-up, as stated in the owner's manual) is more important for all subaru's than anything else IMO.
Castrol is "recycled" oil huh? Care to back that up? And if you mean Group III vs. Group IV oils among the synthetic category, pretty much every big-name brand uses the hydrocracked Group III in full or part formulations, whether they like to print it in the label or not (ehem Mobil 1)
Last edited by rougeben83; 02-01-2013 at 08:45 AM..