the wear factor on new motors is greatest in the first 50 to 100 miles. I changed mine at 67 miles and every 3000miles after that. Is it going to make any difference in the longevity of the motor? I don't know, but I have a 95 F-150 302 that I treated the same way and it has 160.000 miles on it with no mechanical problems yet [engine related]. Wal-Mart sells the correct Motorcraft oil and filter for less than 13 dollars. Cheap insurance.

 

The 3,000 mile mark was old school when engines were not as emission friendly, burned leaded fuel, and the oils did not have todays oil properties. Ford calls for 5,000 mile interval. Can't see any reason not to dod it at 5,000 miles.

 

I just had the oil and filter changed today at the dealer. I have an '05 Lariat SuperCrew. Mileage was 1,100. I will change it every 3,000 miles thereafter. Most of my driving is in town stop and go (heavy traffic).