The 6.4L Power Stroke engine was introduced in 2008 and was the first engine in the light truck market to use dual turbochargers and a diesel particulate filter (DPF) to reduce emissions. Despite being able to increase horsepower and torque, it had issues with fuel economy and reliability. The engine was retired after 2010 and replaced by the 6.7L Power Stroke built by Ford. It has a 3.87 in × 4.13 in bore and stroke, resulting in a total displacement of 388 cubic inches. It features a compound VGT turbo system and has a DPF and dual EGR coolers to reduce exhaust gas temps. The engine computer is programmed to periodically inject extra fuel in the exhaust stroke to burn off soot in the DPF.