There are a few used v-10s around here. They are cheaper than the F-150s similarly equiped. A personal quote I've heard was the V-10 gets 11-16mpg, which is what my 93 5.0L 4x4 gets now. Also, those V6 suvs get 16-23mpg. To me there isn't much difference to worry about. I like power, I'll get it if I can afford it.

On the other hand, V10 maintenence is probably outrageous. This probably doesn't help at all.