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.
Synthetic oil requires changing anywhere from 5,000 to 15,000 miles, while drivers generally change traditional oil every 3,000 miles. The length of time between oil changes varies depending on the make and model of cars, along with age and the oil ingredients.