Amendments to the Test Procedures for Heavy-Duty Engines, and Light-Duty Vehicles and Trucks and Amendments to the Emission Standard Provisions for Gaseous Fueled Vehicles and Engines

On September 5, 1997 EPA promulgated a direct final rulemaking that amended several sections of the heavy-duty engine test procedure regulations. EPA also published a notice of proposed rulemaking proposing the same amendments. EPA noted that if adverse comments were received regarding any provisions, EPA would withdraw those provisions and comments would be addressed in a later final rule based on the proposed rule. Due to adverse comments that were received regarding three provisions, EPA issued a final rule on May 4, 1998 withdrawing those three provisions and indicated that they would be addressed in a separate action. Today, EPA is finalizing those three provisions with amendments, after taking into consideration comments received during the comment period and further discussions with heavy-duty engine and light-duty vehicle manufacturers.