[BroadHopper]

I always have good luck following the owner manual, regardless of what the dealer and or mechanics say. I normally keep my vehicles for a good 10 years regardless of mileage. Never had I have major engine trouble.
2010 MB requires synthetic lube, 1 year or 13,000-mile interval.
The previous 2000 Jeep requires 1 year or 8,000-mile interval with semi-synthetic lube.
Before the Jeep, 1997 Dodge requires 3,000 or 1 year whichever comes first.

I do know that oil manufacturers suggest you change the oil annually. The chemicals used in the oil dissipates after opening.

As for the brand, I always use Wolf's Head. The generic brand from the company that produces the oil for all major brands. Yes, I change my own oil.