Heavy-duty engines and vehicles; Spark-ignition reciprocating or rotary internal combustion piston engines (HS 8407); Compression-ignition internal combustion piston engines (diesel or semi-diesel engines) (HS 8408); Motor vehicles for the transport of ten or more persons, including the driver (HS 8702); Motor cars and other motor vehicles principally designed for the transport of persons (other than those of heading 87.02), including station wagons and racing cars (HS 8703); Motor vehicles for the transport of goods (HS 8704); Special purpose
motor vehicles, other than those principally designed for the transport of persons or goods (for example, breakdown lorries (wreckers), crane lorries (mobile cranes), fire fighting vehicles, concrete mixer lorries (concrete-mixers), road sweeper lorries (road sweepers), spraying lorries (spraying vehicles), mobile workshops, mobile radiological units) (HS 8705); Quality (ICS 03.120), Air quality (ICS 13.040), Test conditions and procedures in general (ICS 19.020), Road vehicles in general (ICS 43.020), Commercial vehicles (ICS 43.080), Passenger cars.
Caravans and light trailers (ICS 43.100)

Improvements for Heavy-Duty Engine and Vehicle Test Procedures, and Other Technical Amendments (6 page(s), in English)

Notice of proposed rulemaking - This notice of proposed rulemaking includes corrections, clarifications, additional flexibilities, and adjustment factors to improve the Greenhouse gas Emissions Model (GEM) compliance tool for heavy-duty vehicles while more closely matching the outputs produced by the original GEM version 3.0 that was used to establish the CO2 standards for Model Years 2021 and later in the 2016 Heavy-duty Phase 2 final rule. This document supplements the proposed rule published on May 12, 2020, which included a larger set of proposed revisions to modify and improve GEM. Most of the proposed revisions from that notice of proposed rulemaking are addressed in a final rulemaking published elsewhere in the Final Rules section of this issue of the Federal Register. Given the nature of this proposal, there will be neither significant environmental impacts nor significant economic impacts for any sector. If requested on or before 6 July 2021, the EPA will host an online public hearing at 10 a.m. Eastern Standard Time on 14 July 2021.