I bought my 2000F150Supercab4x4 new in May of 2000. I used dino oil for the first 10k miles changing it around 3k each time. Then I switched to Mobil 1 5w30 synthetic and changed it around 5k. The 5.4 engine always used a qt. of oil around 2500 miles until 80k. It went from 80k to 85k using one qt. I changed the oil and it went to 90k using only one qt. That is the longest time that I have experienced for rings to completely seat.

My previous 94 5.0 4x4 F150 had 35k on it when I bought it. The week after, I drove it 1200 miles to a new contract job and it used one qt. of oil. After that it would always go 5k and still would not be quite a qt. low.

I bought a 6 cyl 81 Ford Granada in 82. It had 10k miles on it. It used a qt. every 1500 miles and slowly got better. By 45k, it would still be full at the 3k oil change.

 

you should not use any synthetic oil during breakin. just use regular oil with no additives. this will seat the rings quicker, and make them last longer