I use Mobil One in all my vehicles. I've seen Mercedes that use this oil torn down after 250,000 miles with virtually zero wear (the car in question blew a head gasket after the operator failed to replace a radiator hose that, believe it or not, appeared to be the original item). The one thing they had done was change the oil every 15,000 miles (this is the recommended interval for Mercedes not operating in a desert climate - I'd change this to 12,000 then).
The oil is pricey, but as you can see, you'll be running it a lot longer.
"You can never be free until you let yourself go."