I have a 1993 Ford F-150 extended cab, 302 V8, automatic. Had it since new and has 409,165 miles on the original engine. Only thing replaced is A/C, Starter and Alternator(just replaced them last year with about 395,000 miles). Transmission rebuilt three times. We used regular Havoline 10W-40 with MotorCraft FL-1A filters for the first 150,00 to 200,000 miles then swithched to regular Castrol 10W-40 with FL-1A. There also has been several(10-20)times that there was different oil and filters used because being out of town and definately needed an oil change. We tried to change every 3,000 but not every time. The trucks odometer goes to 399,999 and then flips right back to 300,000. I had my camera ready for the 400,000 and was dissapointed when it said 300,000. The last 15,000 miles we have a bad oil pan leak and we have not fixed and won't. just saving money to replace the motor. It is a work truck and has been very very good to us. No additives for anything just regular maintenance on the entire engine. Or it is just because it is A FORD!!!!!!!
(Three transmission rebuilds in 400,000 miles dosen't sound good at all, most properly maintained transmissons can last 200,000 miles before a rebuild.) However, Ford trucks seem to be better built than Ford cars and 400,000+ miles on the original engine without a rebuild is very good. I've had my fill of domestic cars, trucks on the other hand are another story.
(Three transmission rebuilds in 400,000 miles dosen't sound good at all, most properly maintained transmissons can last 200,000 miles before a rebuild.) However, Ford trucks seem to be better built than Ford cars and 400,000+ miles on the original engine without a rebuild is very good. I've had my fill of domestic cars, trucks on the other hand are another story.