All depend on operating habits..
Highway miles all time where engine is wound up and plenty good and hot, then 5-7500 mile be fine with plain oil. Short trip kinda stuff aorund town, 3-4000 be better choice, as engine not get good and hot to burn off moisture and blow by contaminants in the crankcase.
Little fun,, my daily beater had 355,600 here this past Christmas with plain old Castrol GTX every 3-5,000 mile, had to finally install rings (oil rings stuck in place) and bearings, and all seals, but it back on road again with bit over 3500 mile since first of Jan 2012..
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