Ford Motor Co. is hoping to keep its product revolution rolling by introducing for the first time its own diesel engine into the heavy-duty pickup truck segment. The new diesel engine, powering the new F-Series Super Duty truck, resulted from a development program that began as Ford’s longtime relationship with Navistar broke down amid recriminations and lawsuits over pricing, specifications, quality standards and warranty costs. Navistar had supplied Ford with the big-diesel engines used in the heavy-duty pickup trucks for more than two decades. Ford elected almost three years ago to build its own diesel engine for its North American...