The late 1990s saw a rise in demand for diesel-powered engines, which provided superior torque, improved fuel economy, and greater towing power. Two of the most prominent players in this market were Ford and Navistar, who, recognizing the impending regulations for nitrogen oxide (NOx) emissions, teamed up to develop a new diesel engine platform.
Their collaboration gave birth to the 6.0L Power Stroke engine in 2003. The decision to move on from the highly-acclaimed 7.3L Power Stroke engine was largely driven by the need to meet the stricter governmental emissions requirements while staying competitive in the market. Although the 7.3L was highly regarded for its power and reliability, its use was cut short by new emmision regulations.
The 6.0L Power Stroke engine used various advanced emissions control equipment, including a new Variable Geometry Turbocharger (VGT), to produce more power and fewer emissions. The VGT offered an increased throttle response and better exhaust flow by altering the size of the turbocharger housing based on the throttle position. At lower RPMs, the housing became more restrictive, while the vanes opened up at higher RPMs.
The new cylinder heads of the 6.0L Power Stroke engine had four valves per cylinder, which allowed for increased airflow, and a new fuel injection system that used spool valves instead of poppet valves. The spool valves enabled higher oil pressure output and a more efficient combustion process.
When it debuted, the 6.0L Power Stroke engine boasted 325 horsepower and 560 lb-ft of torque, which was a 50 horsepower upgrade over the 7.3L Power Stroke engine. However, despite the many improvements, the 6.0L Power Stroke engine suffered from some reliability issues, including the failure of the oil cooler, EGR cooler, high-pressure oil pump, and head gasket, among others.
Although many 6.0L Power Stroke engines are still in service today, the engine's reputation for unreliability led to its discontinuation in Ford's Super-Duty pickups after the 2007 model year. The engine remained in use in E-Series vans until the 2010 model year.
The 6.0L Power Stroke engine was a product of the collaboration between Ford and Navistar, driven by the need to meet stricter emissions requirements and remain competitive in the market. It featured several innovative advancements, such as the VGT and the spool valve fuel injection system. Although the engine experienced some reliability issues, it served as a stepping stone towards the development of more advanced diesel engines, which continue to provide superior performance and fuel efficiency.