A fleet manager reading the October 25, 2016 Federal Register faces a purchasing horizon, not a command to replace every truck overnight. EPA and NHTSA's final Phase 2 program sets emissions and fuel-consumption standards for new medium- and heavy-duty vehicles and engines. The rule becomes effective December 27, but its model-year requirements arrive on a different schedule. [2016-21203][2015-15500]

The final program phases toward model year 2027, with interim standards for 2021 and 2024 and EPA requirements beginning in 2018 for certain trailers. Its categories cover combination tractors, trailers used with them, heavy-duty pickups and vans, and vocational vehicles. There are also separate standards for engines powering tractors and vocational vehicles. A single fleet may therefore encounter more than one regulatory category. [2016-21203][2015-15500]

The July 13, 2015 proposal had already set out a long phase-in and the distinction between vehicle and engine requirements. It is useful for understanding the program's development, not for substituting proposed specifications for final ones. The final document says some standards were strengthened and others adjusted after further information. Both sources come from the same joint rulemaking, not independent tests of fleet performance. [2016-21203][2015-15500]

Our practical reading is to match a planned purchase to its vehicle category and model year before treating the effective date as a purchasing deadline. Agency estimates of fuel savings are projections, not money already saved by an operator. The rule's promise concerns future efficiency; these documents do not establish a particular fleet's costs, a driver's earnings, or the results of a vehicle already in service. [2016-21203][2015-15500]

Source documents

  1. Greenhouse Gas Emissions and Fuel Efficiency Standards for Medium- and Heavy-Duty Engines and Vehicles-Phase 2https://www.govinfo.gov/content/pkg/FR-2016-10-25/html/2016-21203.htm
  2. Heavy-duty vehicle Phase 2 proposalhttps://www.govinfo.gov/content/pkg/FR-2015-07-13/html/2015-15500.htm