Navistar company International Truck and Engine Corporation has confirmed it is supplying Ford's new 6.4-litre 'Power Stroke' diesel engine for the 2008 F-Series Super Duty.

The new engine, 400cc larger than the current six-litre V8, also supplied by the Navistar unit, will be the first pickup engine in North America to use a high-precision, high-pressure, common-rail fuel injection system with piezo-electric injectors which allow ultra-precise timing of fuel injection for quietness and better emissions.

International recently invested more than $100m in new machinery and other equipment at its manufacturing facilities in Indianapolis and Huntsville, Alabama to manufacture Ford's new diesel.

Diesel engines have become the powertrain of choice for heavy-duty pickup truck buyers in the US because they provide more torque for maximum towing and hauling with improved fuel economy.

Industry-wide diesel heavy-duty pickup and chassis sales from 1994 to 2006 grew at an average rate of 9% per year, according to RL Polk & Co. In 2006, 69% of these trucks sold were diesel powered.

Ford's F-Series Super Duty trucks, powered by the Power Stroke diesel, are the most popular vehicle in their class, averaging 50% market share in the heavy-duty pickup truck segment during the past five years.

But the relationship between engine and truck makers has had its moments. Three years ago, Ford was reported to be buying back some Power Stroke engine-equipped trucks due to buyer concern over problems with fuel leaking into engine oil and control calibration issues. The automaker claimed at the time only a small number were affected.

Some months earlier, Navistar and Ford settled a dispute over who was to pay for development costs written off after the automaker scrubbed a V6 diesel engine Navistar had been working on for it.

Cummins declines to name light diesel customer

Problems hit new Ford diesel truck

Companies settle over diesel V6 axe