Clean Automotive Technology...
Innovation that Works
                                          United States
                                          Environmental Prnti
        Clean  Diesel  Combustion  -

        Clean,  Efficient;  and Cost  Effective Technology

        Diesel engines are used worldwide because they achieve better fuel economy, lower carbon dioxide
        (CO2) emissions and produce higher levels of power than conventional gasoline engines. However,
        diesel engines tend to be more costly and emit high levels of oxides of nitrogen (NOx) and particulate
        matter (PM) emissions.  While several technology options exist to decrease these emissions, the U.S.
        Environmental Protection Agency (EPA) and  industry partners are evaluating and developing EPA's
        Clean Diesel Combustion (CDC) technology  , which refines several existing technologies into a unique
        engine design that is simultaneously clean, efficient, and cost effective.
           Low Emission Diesel Technology
                          Kydraulically Intensified
                          Fuel Injection System
What is Clean Diesel Combustion?
The method of CDC encompasses a series of design
changes to the diesel engine, which decrease NOx
emissions while maintaining or improving engine
efficiency. The key concept of CDC technology is the
development of in-cylinder NOx control, where NOx
emissions are reduced in the engine  combustion
chamber without penalizing the engine's efficiency.
Preliminary EPA research has demonstrated positive
results for a design that achieves in-cylinder NOx
emissions much lower than levels reported by industry.
                                       To Diesel
        A clean diesel combustion engine with its various components.
         Key Features of CDC Technology

         •   EPA Fuel System - Uses a hydraulically intensified fuel
            system to lower PM and smoke emissions, and improve
            engine efficiency.

         •   Boost System - Increases the engine power and the
            efficiency of the combustion process, thus reducing
            emissions and increasing fuel economy.

         •   Low Pressure Exhaust Gas Recirculation (EGR) - Lowers
            the peak combustion temperature to reduce the formation
            of NOx.

         •   PM Aftertreatment - Reduces the remaining smoke,
            unburned hydrocarbons (HC) and carbon monoxide in the
            exhaust to levels required for future emissions standards.
                                   NOx Emissions
                         Engine Speed [rpm]

               This real engine test map shows that NOx emissions
               are low over the entire engine operating map. Brake
               mean effective pressure (BMEP) is a measure for
               comparing performance of one engine to another.

Clean  Automotive Technology...
Clean,  efficient, cost-effective
         Technical challenges include lowering participate emissions coming directly from the engine,
         demonstrating the robustness of the technology in real world operation, and keeping cost/durability
         relative to other approaches for meeting future stringent diesel emission standards. EPA continues to
         improve the development of this technology by addressing these issues.
         Benefits of CDC

         CDC, with its unique combination of technology
         advances, offers benefits such as:

         •  Low Cost- In-cylinder NOx control (where NOx
            emissions are reduced in the engine combustion
            chamber) greatly simplifies the aftertreatment
            system requirements (conventional
            aftertreatment to reduce smoke, PM, and HC).

         •  Low Emissions - Potential to achieve levels of
            2007/2010 Heavy-Duty Engine and Tier 2
            emission standards without the use of NOx

         •  Scalable - Applicable to both light-duty and
            heavy-duty diesel engines.
                                       Brake Thermal
                                       Efficiency [%]
                1000  12M
                       I860  1700  2000
                      Engine Speed [rpm]

           This real engine test map shows a high level of engine
           efficienty at various speeds and ooads. For this test, the
           boost was externally supplied, simulating a well-matched
           turbocharger (P exhaust = P input + 1.5 psi)
         Technology Advances to Achieve Emission Standard Levels

         EPA emission standards - both 2007 heavy-duty engine and the Tier 2 standards for passenger vehicles -
         call for major  reductions (ranging from 77 to 95 percent) in NOx and PM emissions.  Although several
         methods are being examined to meet these future standards, today's primary path option to reduce diesel
         NOx emissions is through the use of aftertreatment devices.  NOx aftertreatment devices control emissions
         downstream from the engine's combustion chamber, in the exhaust system rather than in the engine.
           2007: Highway Diesel NOx Standards





1985 - uncontrolled levels



• NOx aftertreatment-based
• 0.2 g/bhp-hr
• -90% reduction
2004 f
           For model year 2007, NOx emission standards for heavy-
           duty engines are reduced over 90% of current standards.
Research on CDC technology suggests that cost-effective
alternatives for long-term NOx compliance may not need to
rely exclusively on NOx aftertreatment methods. CDC
technology may be an attractive alternate method to achieve
future stringent diesel emissions standard levels.
                                                Currently, EPA is actively discussing CDC technology with
                                                potential partners to continue advancing the research and
                                                possibly introduce the concept into production in the future.
                                                                                        March 2004