MMTA Submits Comments on EPA’s Proposed Low-NOx Rule

Below is a message from ATA on the need for public comment on this rule:

On March 28, USEPA published its proposed low-NOx emissions rule (“HD2027”) that will take effect beginning in 2027. The last NOx standards for new trucks was finalized in 2001 and implemented between 2007 and 2010 – more than two decades ago. Many states, led by California and its California Air Resources Board (“CARB”), are interested in lowering NOx emissions for new trucks by up to 90% from the current federal standard and promoting pathways towards the adoption of zero-emission vehicles. Rather than impose a patchwork based on CARB’s proposed pathway to lower emissions, ATA supports a single, standardized final rule to reduce NOx emissions that is implementable, cost-effective, does not disrupt truck buying cycles, and serves as a bridge to the transition to zero-emission vehicles. The two Options presented under the proposed rule are as follows:

  • Option 1: A two-phased approach to achieve a 90% reduction in NOx emissions by 2031 (cutting NOx emissions from 0.2 to 0.035 grams by 2027 and from 0.035 to .02 grams by 2031), with an 84% increase in the useful life period (from 435,000 to 800,000 miles) and a 500% increase in the emission warranty period (from 100,000 to 600,000 miles) by 2031.
  • Option 2: A single-step approach to achieve a 75% reduction in NOX emissions (from 0.2 to .05 grams) by 2027, with a 38% increase in the useful life period (from 435,000 to 600,000 miles) and a 250% increase in the emission warranty period (from 100,000 to 350,000 miles).

Option 1 mirrors CARB’s final rule in 2027 (i.e., a 90% NOx reduction from the current federal standard. Option 2 is the approach being advocated by OEMs. The final rule may likely end up being somewhere between these two Options. Testimony at the 3-day EPA Public Hearings in Mid-April were 99% in favor of the more stringent standards (Option 1) as well as eliminating the use diesel vehicle altogether.


Submitting your comment is easy. Go to the federal rulemaking portal at; scroll down to “What’s Trending”, click on “Control of Air Pollution from New Motor Vehicles: Heavy-Duty Engine and Vehicle Standards”, click on the “Comment” button; then upload your comments and submit. The docket number for the rule is “EPA-HQ-OAR-2019-0055”. Feel free to embellish the comment form letter as you wish. This rule has the potential to be the most expensive rule in the history of our industry and your support is greatly needed.