• Powertrain data;
• additional aerodynamic test data;
• supplemental test data relating to drive cycles (and frequency thereof) for vocational vehicles; and
• cycle average mapping data.

Docket IDs are EPA–HQ–OAR–2014–0827 (for EPA’s docket) and NHTSA–2014–0132 (for NHTSA’s docket).

The two agencies are also soliciting additional comment on certain revised test reports, and a revised version of the Greenhouse Gas Emission Model (GEM) used both in developing certain of the proposed standards and in demonstrating compliance with those standards.

Additionally, EPA is soliciting further comment on memoranda relating to standard applicability and implementation. These memoranda address potential requirements for selective enforcement audits and confirmatory testing related to greenhouse gas emissions, and applicability of emission standards and certification responsibilities for trailers, glider vehicles, and glider kits.

Comments are due by 1 April 2016.

Background. As proposed in 2015, the Phase 2 vehicle and engine performance standards would cover model years 2021-2027, and apply to semi-trucks, large pickup trucks and vans, and all types and sizes of buses and work trucks. They would achieve up to 24% lower CO₂ emissions and fuel consumption than an equivalent tractor in 2018, based on the fully phased-in standards for the tractor alone in a tractor-trailer vehicle.