neither... Any extended performance oil will do. I run Mobil 15k mile interval on all 4 of our cars, all with over 200k on the clock. I quit wasting time and money changing my oil all the time years ago.
Been changing my oil between 8k-10k mi for the past 4 years on my '05. I mostly use Mobil 1 0w20. I did use M1 high mileage full synthetic once a few years ago. But I still changed that oil at around 10k, nevertheless. Just can't bear to wait that long...15k mi.