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.
October 29, 2010 at 1:50 pm. There is a lot of debate over the oil change interval, which is now up to 15,000. First there is no argument that a synthetic oil can run longer between oil changes.