ACEEE filed comments in response to an EPA notice of proposed rulemaking, “Control of Air Pollution from New Motor Vehicles: Heavy-Duty Engine and Vehicle” (87 FR 17414). The United States needs strong medium- and heavy-duty vehicle standards to make the needed progress toward the Biden administration's 2030 greenhouse gas reduction and electric vehicle goals. The comments argue that the EPA has underestimated electric vehicle sales and, therefore, proposes much too lenient emissions standards. The proposal also does not do enough to limit the damage from outdated credit programs. Stronger standards are possible and achievable.