i have a 1997 F150 5.4L i bought from my grandfather when he got his 2004 and he special ordered the 1997 and recived it in november or december of 1996. my 1997 has 78,700 miles on it. the motor has piston slap. the oil has been changed every 5,000 miles when he had and it i change it every 3,000 with penzoil high milage 10w-30. i also put a IAC on it. the truck runs like it si brand new still. i pull a 18 foot ranger bass boat with it and today i just pulled a heavy old car trailer filled with furniture, washer and dryer, and fridge. pulls everything and feels like its not even tryin hard to do it.

 

my uncle traded his 00 expidition with 5.4L in it used full synthetic since it was brand new sold is couple weeks ago with 211,000 miles on it no signs of wear what so ever.