Sullivan, Lummis Introduce Legislation to Fix Onerous Cold Weather Roadblocks for Diesel Engines

WASHINGTON-U.S. Senators Dan Sullivan (R-Alaska) and Cynthia Lummis (R-Wyo.) recently introduced the Cold Weather Diesel Reliability Act to address Environmental Protection Agency (EPA) emissions system malfunctions that can force diesel engines to shut down in extreme cold. Under current one-size-fits-all EPA regulations, trucks and heavy equipment are required to use emissions systems that can trigger engine shutdowns when diesel exhaust fluid (DEF)-which freezes at just 12 degrees Fahrenheit-fails to reach proper operating temperatures, even though the engine itself is working normally. This legislation directs the EPA to update its regulations to account for how diesel engines actually operate in cold-weather states, like Alaska and Wyoming, to prevent the automatic shutdowns caused by cold-related emissions faults, and to provide year-round exemptions from DEF system requirements for vehicles and equipment that operate primarily in cold weather climates.

"In extreme cold, diesel engines can shut down because EPA-mandated emissions systems weren't designed for the harsh conditions we face in Alaska and across the northern United States," said Sen. Sullivan, "That's not just an inconvenience, it's a compliance trap for the men and women who keep Alaska moving. The Cold Weather Diesel Reliability Act makes sure trucks and heavy equipment can keep operating safely in freezing weather by preventing automatic shutdowns caused by cold-related emissions faults. Our legislation brings common sense to EPA rules, aligning federal policy with real-world conditions in the nation's coldest regions."

"Climate-alarmist bureaucrats in Washington do not understand that the consequences of their radical agenda are hurting real people in western communities," said Sen. Lummis. "I am proud to join Senator Sullivan in correcting the Obama and Biden administrations' disastrous policies and ensuring folks don't get stranded in their 'EPA-compliant' vehicles, even during the harshest winter weather. The people of Wyoming should not have to choose between breaking the law or losing their lives."

"Alaska is not only a cornerstone of America's resource development and national defense-it is also one of the most logistically challenging environments in the country," said Ryan Anderson, commissioner of the Alaska Department of Transportation and Public Facilities. "Reliable, year-round transportation is the backbone of our economy, our communities, and our national security readiness. But current federal emissions regulations too often fail to account for the realities of operating in Arctic conditions, where subzero temperatures can disable critical diesel systems and strand operators in life-threatening situations. The Cold Weather Diesel Reliability Act ensures that truckers, maintenance crews, and equipment operators can keep moving safely and effectively in extreme cold, without being sidelined by systems never designed for this environment. It's a common-sense fix that protects lives, supports economic activity, and strengthens our nation's ability to operate in the Far North."

"Alaskans face exceptional challenges daily. Laws and rules are made without consideration for extreme weather with the sub-zero conditions we often endure," said Justin Hargrove, owner of Different Strokes of Alaska. "Our industries here sometimes require exception for dependability of our equipment to complete the already complex, dangerous and arduous jobs. We need not be encumbered by things we can change, specifically if they can make enough of a difference to prevent hard working Americans and vital industries from risk. Emissions regulations that are already waived for the Department of Defense, because of the locally recognized environmental challenges, should be considered for the civilian population for the same benefit. With the current blanket emissions standards for non-DOD, our diesel engines in Alaska are unreliable and can ultimately put lives in jeopardy. Making a subtle change to diesel regulation in Alaska will save lives, increase productivity, provide reliability and help to remove a proven dysfunction that needlessly challenges Americans here nearly half of their lives."

"On behalf of United Freight and Transport, Inc., a commercial carrier based in Alaska, I write to express our strong support for the Cold Weather Diesel Reliability Act of 2025," said Samantha Brown, corporate director & manager of health and safety compliance for United Freight and Transport, Inc. "We believe this legislation is essential for safeguarding both public and driver safety throughout the Arctic and sub-Arctic regions we operate in daily. Alaska's extreme cold weather presents unique and dangerous challenges for commercial drivers. Current emissions control systems, particularly shutdown and derate functions triggered by faults in sub-zero temperatures, can leave vehicles stranded in remote, rugged terrain with limited emergency access. This poses serious safety threats, including hypothermia, frostbite, or delayed response in life-critical deliveries and rescue operations. By allowing engine manufacturers to suspend derate or shutdown functions during cold weather, this bill provides a crucial operational safeguard. It ensures that trucks remain mobile, and drivers remain protected without compromising long-term emissions compliance. The ability to maintain vehicle performance under such conditions is not just a matter of convenience, it is a matter of life and death in Alaska's most isolated regions. We urge swift passage of this important legislation and appreciate your commitment to common-sense safety measures that respect both environmental responsibility and human life."

"Farmers and ranchers in cold climate states have long awaited exemption from DEF requirements in cold climates. It will be a great relief from the problems it has caused our equipment, and added expense to our supply chain," said Scott Mugrage, president of the Alaska Farm Bureau. "This exemption has our full support."

Senator Sullivan has long pushed back against heavy-handed overreach from federal agencies, like the EPA, especially the aggressive Biden administration EPA's enforcement actions in Alaska, including armed raids on small mechanics in the Mat-Su. Earlier this year, Sen. Sullivan secured a commitment from EPA Administrator Zeldin to work with him to rein in these rogue enforcement tactics and to review impractical regulatory requirements that don't work in Alaska's extreme conditions.

# # #