After recent disagreements with engine supplier Navistar, as well as dealing with Super Dutys that perform roman candle impressions, Ford is accelerating development of a new diesel engine for its burliest of pickups. Ford and Navistar played chicken earlier this year over warranty costs for the older 6-liter Powerstroke V8. That engine had a high number of issues that led to Ford covering repair costs. Ford in turn sued Navistar, the engine supplier, and held back payments for the new 6.4-liter Powerstroke in an effort to recoup some of their expense. Navistar decided they'd have none of it, and shut down engine production, slowing Super Duty production until a court order got the engines flowing again.
This acrimony has spurred Ford to come up with an alternative to Navistar engines in one of its most pivotal vehicles. The diesel and its muscle-bound tow rating attract plenty of buyers, and the Super Duty is at the top of the Ford Truck food chain, so problems here look bad. If your work truck doesn't work, you're in trouble. Ford can't afford to lose the profits from the Super Duty, nor can it accept tarnishing the image of the iconic F-Series trucks, so the Dearborn team is on it in the interest of exorcising Navistar powerplants from the engine bay and keeping that customer cash flowing.