Before this big, bad pickup arrived, manufacturers largely used upgraded versions of their light-duty trucks to handle heavy-duty work. The 1999 Super Duty was a separate model line with its own style and hardware underneath.
You can run a conventional oil 5K miles but you should be able to run a synthetic oil 7500 to 10000 miles. Royal Purple API-licensed synthetic engine oils allow motorists to travel as many as 12,000 miles as the recommended oil change interval.
Revised by BoatUS editors in April 2012. Engine manufacturers typically recommend an oil change every 100 hours, and at least once a year. Even if your engine manual allows for a longer interval between oil changes, changing the oil more often will extend the life of the engine.