Considering that this unit is totally unlike a conventional automatic (it has no clutches, gear changes, sliding parts, etc.), I bet it could go 500k or more easily. A sensor or shaft seal could fail but the gears are always meshed and spinning on roller element bearings - nothing to really "wear out". My old one likely ran 50k miles after the shaft "failed" with all the teeth corners knocked off one gear, a huge grove worn in the housing and a hole clear through the case. Yet, the other bearings and gears were still almost perfect. Ford had a problem for sure, but I still say the transmission is one of the best features of the car. It never "shifts" (not even for reverse!); just smoothly and continually adjusts drive ratio as needed. You go up and down mountains like they're not even there. And you can shift between forward and reverse without stopping!