80,000 +/- for my filter/pan and fluid change on my '03 shortly after purchase in '19. I learned a great deal right here on these pages about this procedure and did it myself as usual. Used Mercon also, bought from Amazon by the case. I had a slightly harsh 2-1 shift and it went to butter smooth everywhere. I have it back once in a while at high idle when the engine is cold. I will drain and fill again when I get a chance. I have plenty fluid on hand. The Mercon is also available locally at my a Ford dealer. TM