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 oils, such as the popular Mobil 1, are stretching oil change intervals, leaving the 3,000-mile mark in the dust. The great majority of new vehicles today have a recommended oil change interval greater than 3,000 miles, said Mobil spokeswoman Kristen A. Hellmer.he car had an oil life monitoring system, and the system had recommended the past two oil change intervals at 5,500 miles and 7,600 miles on non-synthetic oil.