I don't have one but have read other posts on the V10. Too many variables exist to give a solid number but overall range seems to be 7 to 12 mpg. You can do a post serach at RV.net and ford-trucks.com for additional references.
Me, one great wife who navigates & researches places to go & food to eat, one little boy who can't get enough camping, one border collie who refuses to be left behind!
2004 Fx4 F250 King Ranch SVT CC, PSD, Prodigy, no mods.