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2012
Overview
• The combustion system is the heart of the
6.7L Power Stroke V8 turbo diesel engine and reflects
how Ford engineers achieved a balance of power,
fuel efficiency and reduced emissions
• The key factor to the more-stringent 2010 federal
emissions standards is over 80 percent reduction in
the emission of nitrogen oxides (NOx)
• To help reduce NOx levels, the Power Stroke burns
cleaner in large part because of the design of the
Exhaust Gas Recirculation (EGR) system
• In addition, there is a three-step aftertreatment
system utilizing a Diesel Oxidation Catalyst (DOC),
Selective Catalytic Reduction (SCR) using Diesel
Exhaust Fluid (DEF) and Diesel Particulate Filter
(DPF) as the key components
• This system works in harmony to reduce the NOx
levels within the latest federal standards — making
the 6.7L Power Stroke the "cleanest" Ford Power
Stroke diesel engine ever
Power Stroke Emissions Strategy
• Allows the engine to operate with a leaner fuel
mixture than previous Power Stroke engines
• A leaner fuel mixture has less fuel and more air
• Leaner burning engines produce less
particulate emissions
• Less particulate emissions result in less frequent
DPF regeneration
• Less frequent regeneration helps improve overall
engine fuel efficiency
16
F-250/F-350/F-450
Super Duty Pickups
Performance/Handling
Diesel Engine Emissions
Exhaust Gas Recirculation (EGR)
• Recycles combustion gases in the exhaust system
as the first defense against NOx
• A two-step cooling process allows the EGR to
recycle exhaust gases into the intake at a much
lower temperature
• A cooler temperature means a higher efficiency in
recycling the exhaust gases and less oxygen in the mix
• Less oxygen helps reduce the formation of NOx in
the exhaust
Diesel Oxidation Catalyst (DOC)
• The first step in the exhaust aftertreatment
process and could be referred to as the cleaning
and heating step
• Converts and oxidizes hydrocarbons into water and
carbon dioxide
• Provides and promotes heat into the exhaust system
to help increase the conversion efficiency
Selective Catalytic Reduction (SCR)
• The second step in the exhaust aftertreatment
process, primarily where NOx is removed from
the exhaust stream
• Located between the DOC and the DPF in the
exhaust system
• Uses a liquid chemical reactant, Diesel Exhaust
Fluid (DEF)
• DEF Dosing Module sprays a fine mist of DEF into the
exhaust stream to react with the NOx in the exhaust
as it passes through the SCR Catalyst
– When heated, DEF splits into ammonia and
• These molecules are atomized and vaporized and
evenly distributed into the exhaust flow
• Once the DEF solution is combined with the exhaust
flow, chemical reactions convert the ammonia and
NOx into water and harmless nitrogen
esourcebook.dealerconnection.com
RE&T: 2012 Source Book
carbon dioxide
June 2011
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