Federal News
Senate Advances Cold Weather Diesel Reliability Act
March 13, 2026
The Senate Environment and Public Works Committee held hearings on the Cold Weather Diesel Reliability Act, introduced by Senators Dan Sullivan and Cynthia Lummis, to address operational challenges caused by EPA diesel emissions regulations in extreme cold climates such as Alaska, Wyoming, and Nebraska. The legislation aims to amend EPA rules that currently cause diesel engine shutdowns due to diesel exhaust fluid (DEF) system malfunctions in cold weather, which impact emergency response, agriculture, and transportation sectors. This effort seeks to balance emissions reduction goals with the need for reliable diesel engine operation in harsh winter conditions, improving safety and supply chain continuity in affected states.
- Why this matters: Procurement professionals should anticipate potential regulatory changes affecting diesel-powered vehicle and equipment specifications, especially for agencies operating in cold climates.
- Agencies and contractors in Alaska, Wyoming, and Nebraska may see revised requirements or exemptions for DEF systems, impacting maintenance contracts and equipment procurement.
- Vendors supplying diesel engines, emissions control systems, or related maintenance services should evaluate how the legislation could alter product demand or compliance standards.
- Organizations involved in emergency response and agriculture logistics should prepare for improved operational reliability and potential procurement opportunities tied to updated diesel system standards.
A major grievance is that when a DEF sensor fails or a system malfunction, it often triggers limp mode, where a tractor or combine loses power and speed, causing critical delays during planting and harvesting.
— Pete Ricketts
None of us are saying we shouldn’t do anything about NOx and SOx, but we do need to have regulations that are not a one-size-fits-all that really, really penalizes states like mine in a huge way.
— Dan Sullivan
The EPA under Biden knew the DEF systems didn’t work well and posed a risk to public safety, and they mandated them anyway.
— Cynthia Lummis
Agencies
Senate Environment and Public Works Committee, Environmental Protection Agency, Alaska Department of Transportation and Public Facilities, Senate Western Caucus
Locations
Sources
- EPW Committee Holds Hearing On Sullivan’s Cold Weather Diesel Reliability Act · Sullivan Senate · Mar 12
- Senate Western Caucus Members Push for Commonsense Cold Weather Diesel Reliability Act » Senator Cynthia Lummis · Lummis Senate · Mar 13