United States           Office of Transportation                                 EPA420-F-05-019
Environmental Protection    and Air Quality                                        June 2005

                        C/.^. Environmental Protection Agency (EPA) is revising the
                   procedures for testing various categories of nonroad engines. We are also
                   applying these same procedures to heavy-duty highway 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.
                    As part of our initiative to update the content, organization and writing style of
                    our regulations, we are revising our test procedures. We have grouped all our
                    engine-dynamometer and field-testing procedures into one part entitled, "Part
                    1065: Engine-Testing Procedures."

                    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 individual sectors, the more
                    recent regulations featured test procedure updates and improvements that the
                    other sectors did not have. As this process continued, we recognized that a
                    single set of test procedures would allow for improvements to occur simulta-
                    neously across engine and vehicle sectors. In addition, a single set of test
                    procedures is easier to understand, and it is easier to move toward interna-
                    tional test procedure harmonization if we specify only one set of test proce-

This rulemaking will create unified testing requirements for all engines, which
when implemented will streamline laboratory efforts for EPA and industry.
Overview of the             Regulations
Part 1065 is also advantageous for in-use testing because it specifies the same
procedures for all common parts of laboratory and field testing. It contains
new provisions to help ensure that an engine's operation 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 improved
clarity, we are making a variety of changes to improve 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 calculations 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 specification 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, recreational
vehicles, and nonroad spark-ignition engines over 19 kW. We are also adopt-
ing the lab-testing and field-testing specifications in part 1065 for all heavy-
duty highway engines. In the future,  we plan to apply the test procedures
specified in part 1065 to other types  of engines, so we encourage companies
involved in producing or testing other engines to stay informed of develop-
ments related to these test procedures.

For heavy-duty  highway engines, the procedures in part 1065 replace those
currently published in 40 CFR part 86, subpartN. We are scheduling a
gradual transition from the part 86 procedures. We will allow the use  of part
1065 procedures as an option through the 2009 model year. Starting in the
2010 model year, part 1065 procedures will be required for any new testing.
For all testing completed for 2009 and earlier model years, manufacturers may

continue to rely on cany over 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.

The previous version of part 1065 included regulations for portable emission
measurements systems (PEMS). In this rule, we have revised those regulations
to reflect current state of the art PEMS technology. PEMS measurements
generally rely on the same types of analyzers as those used in laboratory
testing, but they need to be smaller and more durable. The main differences
between PEMS and laboratory systems are that, with PEMS, emissions are
sampled from the raw undiluted exhaust, and engine power is calculated using
signals from the engine computer rather than being measured using a laboratory
dynamometer. For more information about PEMS testing, see the Technical
Support Document for the Heavy-Duty In-Use Testing Final Rule (EPA420-
R-05-006, June 2005).

We are also adopting a requirement that manufacturers of heavy-duty highway
engines use ramped-modal testing to show that they meet steady-state emis-
sion standards using the Supplemental Emissions Test (SET). Much like the
part 1065 procedures, the ramped-modal testing is optional through 2009 and
becomes mandatory in the 2010 model year. The conventional approach for
steady-state testing is to measure emissions separately for each mode.
Ramped-modal testing involves a single, continuous emission measurement as
the engine operates over the test modes in a defined 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 final rule on the Office of Transportation
and Air Quality Web site at:


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