One more great example of a salesman 'tard. DEF (diesel exhaust fluid) is used with a catalyst in the exhaust system to convert the NOx to harmless nitrogen and oxygen. The regen process (exhaust filter cleaning) is employed to burn off the black diesel exhaust soot that is collected in the DPF (diesel particulate filter). Ford injects raw diesel fuel into the exhaust stroke on one side of the engine which travels downstream and heats the DPF to a high enough temperature that the soot is converted to harmless ash.

The salesman is a DORK.

Here's some good reading: http://media.ford.com/images/10031/S...rtreatment.pdf

And a good statement from Ford:

The combustion system is the heart of the new 6.7-liter Power Stroke V-8 turbocharged diesel engine and in many ways encapsulates the careful balancing act the Ford team achieved in terms of power, fuel economy and reduced emissions. The key factor in the next round of federal emissions standards, which begin in 2010, is the reduction of oxides of nitrogen (NOx). To help reduce NOx, the new Power Stroke burns cleaner, thanks to an innovative way Ford developed to cool the exhaust gas recirculation (EGR) to efficiently recycle the combustion gases in the system.

Ford’s system runs the engine with the least amount of oxygen possible in order to reduce NOx without degrading performance and fuel economy. Ford’s solution runs the EGR through a two-step process utilizing separate cooling sources, something not typically seen. The end result is the EGR is brought into the intake at a lower temperature, which means more of it can be utilized, creating greater efficiency throughout the system.

A unique piston bowl design and the high-pressure fuel-injection equipment are huge enablers in achieving the balance of power and lower emissions. The system can deliver up to five injection events per cylinder per cycle, while eight holes in the injector spray fuel into the bowl.

The compressed-air ignition unique to diesels is aided by pilot fuel injections before the piston reaches the top, allowing the charge to heat up even hotter than what you get under normal compression.

“Then when the main injection occurs, we can mitigate NVH because we have a slower ignition process,” said Gryglak. “When the fuel burns, it doesn’t burn with a traditional pop or bang. The direct-injection system is calibrated and phased for optimum power, fuel efficiency and NVH.”

The new diesel engine features instant-start glow plugs, allowing quick start even in extremely cold temperatures.

How the new Power Stroke meets new emissions standards

The new 6.7-liter Power Stroke V-8 turbocharged diesel will employ an aftertreatment system to help comply with 2010 federal regulations to reduce nitrogen-oxide levels in diesel emissions by more than 80 percent compared with the previous standard. The Ford aftertreatment system is a three-stage process; a key component is the use of Diesel Exhaust Fluid (DEF).

Injection of DEF to reduce NOx is a proven technology that’s been used throughout the automotive industry. Unlike other solutions used to control NOx, the DEF system allows the diesel engine to run at its optimum range in terms of fuel mixture. Some systems require the engine to run richer – which can be harmful to diesel engines – in order to control the NOx.

Step One: Cleaning and Heating – The first step in cleaning the diesel exhaust occurs when the exhaust stream enters the Diesel Oxidation Catalyst (DOC). The role of the DOC is twofold. First, it converts and oxidizes hydrocarbons into water and carbon dioxide. This conversion happens at about 250 degrees Celsius.

Second, the DOC is used to provide and promote heat, using specific engine management strategies, into the exhaust system. Through appropriate thermal management, this heat increases the conversion efficiency of the downstream subsystem(s) in reducing emissions.

Step Two: Knocking Out the NOx – The next step in the process is what’s known as Selective Catalytic Reduction (SCR). In this process, the NOx in the exhaust stream is converted into water and inert nitrogen, which is present in the atmosphere and harmless. Before the exhaust gas enters the SCR chamber, it is dosed with DEF, an aqueous solution that is approximately 67.5 percent water and 32.5 percent pure urea.

When heated, the DEF splits into ammonia and carbon dioxide. These molecules are atomized, and vaporized, then enter a mixer that resembles a corkscrew. This twist mixer evenly distributes the ammonia within the exhaust flow. The ammonia enters the SCR module, which contains a catalyzed substrate, and through chemical reactions combines and converts the NOx and ammonia into the harmless inert nitrogen and water. Dosing occurs between 200 and 500 degrees Celsius.

Step Three: Scrubbing Away the Soot – The final part of the cleansing system for the diesel exhaust gas involves the Diesel Particulate Filter (DPF). The DPF traps any remaining soot, which is then periodically burned away, known as regenerating, when sensors detect the trap is full. The regeneration process sees temperatures in excess of 600 degrees Celsius to burn away soot.