Warranties

Improvements for Heavy-Duty Engine and Vehicle Test Procedures

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 CO<INF>2</INF> 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.

Publication Date: 
Tuesday, June 29, 2021 - 4:00am