By Scout Nelson
The Environmental Protection Agency (EPA) has proposed changes to diesel engine emissions regulations aimed at reducing costs and improving flexibility for equipment owners and manufacturers. The agency says the proposal would maintain most of the environmental benefits of existing emissions standards.
One of the most significant changes would eliminate diesel exhaust fluid (DEF) deratements. Instead of reducing engine power when an SCR system detects a fault, operators would receive audible and visible alerts and could continue working until repairs are made.
The proposal also revises emissions warranty requirements for heavy-duty engines. Coverage would remain closer to current levels at 100,000 miles or five years rather than expanding under the model year 2027 regulations.
Another provision would introduce nonconformance penalties, allowing manufacturers to sell certain 2027 engines that temporarily fall short of NOx standards due to technical challenges. The EPA stated that the underlying 2027 NOx emissions limits would remain in place, preserving most of the expected emissions reductions.
The proposal is of particular interest to agricultural producers who have experienced issues with SCR systems and DEF-related deratements. Nebraska Farm Bureau is reviewing the rule and its potential impact on equipment owners, including warranty coverage and compliance requirements.
Public comments on the proposal are due by August 29, 2026, and the EPA has scheduled virtual public hearings as part of the review process.
Photo Credit: environment-protection-agency
Categories: Nebraska, Equipment & Machinery