Clark, I owned a 2004 Ford F150 V8 5.4, one of the worst engines Ford ever built. I towed a 7x16 motorcycle trailer and also a 7x14 lawn care trailer from time to time. I had the transmission done twice and an alternator replaced. When I traded it in I had 348,735 plus miles on it, I changed the oil around every 5,000 miles with Ford recommended oil. The truck had only 4 miles on the speedometer when I bought it new.
got 386,000 plus miles on our Toyota Sienna van. Just love it. Regular oil changes, and it keeps on going.