The 6.4L Power Stroke was released in 2008 and produced an impressive 350 hp from the factory. The design changes to the 6.4L were made primarily to meet new emissions requirements. The 6.4L Power Stroke is a clean and quiet running engine and the first in it's class to feature factory twin turbochargers to help reduce turbo lag. The 6.4L is also the first Power Stroke engine that utilizes a Common Rail injection system and a Diesel Particulate Filter (DPF) regenerative system that burns off excess soot and ash. While the DPF does a good job of filtering out particulates, it has had a negative affect on fuel mileage. Fortunately, there is an abundance of aftermarket performance options to choose from for the 6.4L Power Strokes that will also help increase power and mileage. Cold air intake kits and performance exhaust systems will get you a few extra ponies while lowering EGT's and increasing fuel mileage. A performance tuner can offer some serious hp gains and also help increase your mpg's.
The 6.4 liter also has a Diesel Particulate Filter (DPF) and dual EGR coolers which are capable of reducing exhaust gas temps by up to 1000 degrees before they reach the EGR valve and mix with the intake charge. The Diesel Particulate Filter traps soot and particulates from the exhaust and virtually eliminates the black smoke that most diesel engines expel upon acceleration. The engine computer is programmed to periodically inject extra fuel in the exhaust stroke of the engine (known as a "regeneration" in F-Series) to burn off soot that accumulates in the DPF. This engine must run on Ultra Low Sulfur Diesel (ULSD) fuel which has no more than 15 ppm sulfur content; using regular diesel fuel will result in emission equipment malfunctions and violate manufacturer warranties.