Improvements for Heavy-Duty Engine
and Vehicle Test Procedures, and
otherTechnical Amendments
T I ^his action proposes to amend the regulations that implement EPA
JL air pollutant emission standards for engines, vehicles, and mobile
equipment in response to concerns raised by the regulated industry in
recent years. The proposed amendments include corrections, clarifica'
tions, flexibilities and other minor changes that do not raise significant

Which Products would be Affected?
The proposed amendments would affect the emission certification of the following products:
	Light-duty vehicles
	Heavy-duty vehicles and engines
	Motorcycles (highway and nonroad)
	Marine engines
	Other nonroad engines and equipment
	Stationary engines
	Portable fuel containers
Who would be Affected by these Changes?
The proposed changes would primarily affect manufacturers seeking certification of any of
the affected products, including importers and secondary manufacturers. The changes to the
emission test procedures would also affect anyone performing certification testing, such as
independent test laboratories. However, other persons such as distributors and end-users may
be indirectly affected by the proposed amendments.
Public Participation Opportunities
We welcome your comments on this proposed rule. Comments will be accepted for 45 days
beginning when this proposal is published in the Federal Register. All comments should be
identified by Docket ID No. EPA-HQ-OAR-2019-0307and submitted at
For additional submission methods, please visit
For More Information
You can access the rule and related documents on EPA's Office of Transportation and Air
Quality (OTAQ) website at: