CFR > Title 40 - Protection of Environment > CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY > SUBCHAPTER C—AIR PROGRAMS (Parts 50–99) > PART 90—CONTROL OF EMISSIONS FROM NONROAD SPARK-IGNITION ENGINES AT OR BELOW 19 KILOWATTS > SUBPART B—Emission Standards and Certification Provisions (§90.101 to §90.129) > 90.117—Certification procedure—test engine selection.

90.117—Certification procedure—test engine selection.

(a) For Phase 1 engines, the manufacturer must select, from each engine family, a test engine that the manufacturer determines to be most likely to exceed the emission standard. For Phase 2 engines, the manufacturer must select, from each engine family, a test engine of a configuration that the manufacturer determines to be most likely to exceed the HC NOX (NMHC NOX) Family Emission Limit (FEL), or HC NOX (NMHC NOX) standard if no FEL is applicable.
(b) The test engine must be constructed to be representative of production engines.

Code of Federal Regulations

[60 FR 34598, July 3, 1995, as amended at 64 FR 15239, Mar. 30, 1999]