Office of Transportation                                 EPA420-F-04-046
^/Cnr\            and Air Quality                                       August 2004
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                      77?e I/. S. Environmental Protection Agency (EPA) is proposing modified
                      procedures for testing various categories of nonroad engines. We are
                      also proposing to apply these same procedures to heavy-duty highway
                      diesel engines. This common set of test requirements is intended to
                      streamline laboratory efforts for EPA and industry and to form the basis
                      for internationally harmonized test procedures for nearly all categories
                      of engines.
                      Background
                      As part of our initiative to update the content, organization and writing
                      style of our regulations, we are proposing revisions to our test proce-
                      dures.  We have grouped all our engine-dynamometer and field-testing
                      procedures into one part entitled,  "Part 1065: Test Procedures." For
                      each engine or vehicle sector for which we have recently promulgated
                      standards (such as land-based nonroad diesel engines or recreational
                      vehicles), we identify an individual part as the standard-setting part for
                      that sector. These standard-setting parts then refer to one common set of
                      test procedures in part 1065.

                      In the past, each engine or vehicle sector had its own set of testing
                      procedures.  There are many similarities in test procedures across the
                      various sectors. However, as we introduced new regulations for indi-
                      vidual  sectors, the more recent regulations featured test procedure
                      updates and improvements that the other sectors did not have.  As this

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process continued, we recognized that a single set of test procedures
would allow for improvements to occur simultaneously across engine
and vehicle sectors.  A single set of test procedures is easier to under-
stand than trying to understand many different sets of procedures, and it
is easier to move toward international test procedure harmonization if
we specify only one set of test procedures. Note that procedures specific
to different types of engines or vehicles, such as test schedules designed
to reflect the conditions expected in use for particular types of vehicles
or engines, will be specified in the standard-setting part.
Overview of Proposal
Part 1065 is also advantageous for in-use testing because it specifies the
same procedures for all common parts of laboratory and field testing.
The proposal contains new provisions to help ensure that engine opera-
tion in the laboratory is much like in-use operation in the field. These
new provisions will ensure that laboratory testing and field testing are
conducted consistently.

In addition to reorganizing and rewriting the test procedures for im-
proved clarity, we are proposing to make a variety of changes to im-
prove the content of the testing specifications, including the following:

   * Writing specifications and calculations in international units.
    Adding procedures by which manufacturers can demonstrate that
    alternate test procedures are equivalent to specified procedures.
   * Including specifications for new measurement technology that has
    been shown to be equivalent or more accurate than existing
    technology.
    Adopting procedures that improve test repeatability and calcula-
    tions that simplify determination of emission mass.
   *  Specifying new procedures for testing engines in the field.
    Defining calibration and accuracy  specifications that  are scaled to
    the applicable standard, which allows us to adopt a single specifica-
    tion that applies to a wide range of engine  sizes and applications.
    Using a more comprehensive set of definitions, references, and
    symbols.

Some emission-control programs already rely on the test procedures in
part 1065, including those for land-based nonroad diesel engines, recre-
ational vehicles, and nonroad spark-ignition engines over 19 kW. We
are also proposing to adopt the lab-testing and field-testing specifica-
tions in part 1065 for all heavy-duty highway engines.  In the future, we
may propose to apply the test procedures specified in part  1065 to other

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types of engines, so we encourage companies involved in producing or
testing other engines to stay informed of developments related to these
test procedures.

For heavy-duty highway engines, the procedures in part 1065 would
replace those currently published in 40 CFR part 86, subpart N.  We are
proposing a gradual transition from the part 86 procedures. We will
allow the use of part 1065 procedures beginning in the 2006 model year.
By the 2008 model year, part 1065 procedures will be required for any
new testing.  For all testing completed for 2007 and earlier model years,
manufacturers  may continue to rely on carryover test data based on part
86 procedures to certify engine families in later years. In addition, other
subparts in part 86, as well as regulations for many different nonroad
engines refer to the test procedures in part 86.  We are including updated
references for all these other programs to refer instead to the appropriate
cite in part 1065.

We are also proposing to require manufacturers of heavy-duty highway
engines to use ramped-modal testing  to show that they meet steady-state
emission standards using the Supplemental Emissions Test (SET), which
applies for model year 2007 and later engines. The conventional ap-
proach for steady-state testing is to measure emissions separately for
each mode. Ramped-modal testing involves a single, continuous emis-
sion measurement as the engine operates over the test modes in a de-
fined sequence, including short transition segments between modes.
Ramped-modal testing offers several  advantages,  including increased
accuracy for measuring very low levels of particulate matter emissions
and substantially reduced testing time.
For More information
You can access documents on this proposed rule on the Office of Trans-
portation and Air Quality Web site at:

       www. epa.gov/otaq/largesi .htm

You can also contact us at:

       U.S. Environmental Protection Agency
       Assessment and Standards Division
       2000 Traverwood Drive
       Ann Arbor, MI 48105
       Voice-mail: (734) 214-4636
       E-mail: asdinfo@epa.gov

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