The announcements follow similar updates from other major truck manufacturers and come as the U.S. Environmental Protection Agency (EPA) considers changes to federal emissions regulations affecting newly manufactured heavy-duty trucks.

Software Updates Extend Repair Window

According to Volvo Trucks and Mack Trucks, the updated software delays DEF-related engine derates and vehicle speed restrictions, allowing drivers additional time to reach a repair facility when emissions system issues occur.

The companies said the updates are intended to reduce unplanned downtime while maintaining emissions compliance and improving operational flexibility for fleets.

“By extending the repair window and increasing the final inducement speed, we are helping drivers keep their trucks on the road and safely reach a service location, reducing the risk of unexpected downtime and supporting the uptime and productivity our customers depend on every day,” said Peter Voorhoeve, president of Volvo Trucks North America.

Rollout Underway Across Multiple Models

Volvo said it has been producing trucks equipped with the updated software since May 2026 on vehicles powered by its D13 VGT and D13TC engines. Many recently manufactured trucks have already received the update through remote software downloads.

Mack has also begun installing the software on new Anthem and Pioneer models equipped with MP13 engines. The company expects the update to be available for all 2024 and newer Mack trucks by the end of the summer, with plans to extend the software to all eligible post-2010 models by the end of 2027.

Jonathan Randall, president of Mack Trucks North America, said the company remains focused on providing customers with solutions that support both regulatory compliance and day-to-day operations.

Industry Responds to Proposed EPA Rule Changes

Volvo Group’s announcement follows similar software updates introduced by Daimler Truck North America and Paccar as truck manufacturers respond to the EPA’s proposed emissions rule.

In June, the EPA proposed eliminating DEF-related engine derates and vehicle speed restrictions on newly manufactured heavy-duty trucks while maintaining emissions standards. If finalized, the proposal would change how manufacturers manage emissions system faults on future vehicles.

For fleets operating existing trucks, manufacturers say the new software is intended to reduce disruptions by allowing more time to schedule repairs before performance limitations are activated.

The TDUSA editorial team creates practical, driver-focused content covering trucking news, industry updates, safety, regulations, and career information for professional truck drivers across the United States. Each article is built to reflect real-world experience, industry developments, and information drivers can use on and off the road.

Last Updated: August 17, 2026

Source: Trucking Dive

Image Source: Mack Trucks

The post Volvo, Mack Expand DEF Software Updates for Heavy-Duty Trucks appeared first on Truck Drivers USA.

The proposal focuses on several compliance requirements affecting model year 2027 and newer trucks but does not change the nitrogen oxide (NOx) emissions standards established under the original rule.

EPA Proposes Changes to Several Compliance Requirements

The EPA’s 2023 rule introduced new emissions requirements for model year 2027 heavy-duty trucks, including nitrogen oxide standards that are 80 percent stricter than previous federal limits.

As part of its latest proposal, the agency is recommending changes to several compliance provisions, including:

• Replacing mandatory engine derates with audible or visual warning systems when diesel exhaust fluid (DEF) issues are detected.
• Returning the emissions compliance period from 650,000 miles to 435,000 miles.
• Returning emissions-related warranty coverage from 10 years or 450,000 miles to five years or 100,000 miles.

The proposed revisions would leave the underlying NOx emissions standards unchanged.

Industry Response Has Been Mixed

Many trucking organizations welcomed the proposed changes to engine derates and compliance requirements. However, the Owner Operator Independent Drivers Association (OOIDA) expressed concern that the proposal does not address the emissions standards themselves.

OOIDA also criticized the proposal to shorten emissions-related warranty coverage, arguing that reduced warranty protection could leave owner-operators and small carriers responsible for costly repairs involving emissions systems.

“If EPA is unable to amend burdensome NOx emissions standards, we believe there are more productive solutions than drastically cutting extended warranty periods for small business truckers at the behest of engine manufacturers and large fleets,” said Jay Grimes, OOIDA’s director of federal affairs.

Grimes added that warranty coverage should continue protecting truck owners from repeated and expensive emissions system failures that drivers have reported under previous emissions regulations.

Public Comment Period Runs Through August 29

The EPA is accepting public comments on the proposal through Aug. 29, 2026.

Drivers and other stakeholders can submit comments through Regulations.gov using docket number EPA-HQ-OAR-2026-0728.

The agency will also hold two virtual public hearings:

• July 29 at 9 a.m. Eastern.
• July 30 at 10 a.m. Eastern.

Anyone wishing to testify must register in advance by emailing EPA-HD-MobileSource-Hearings@epa.gov. According to the EPA, registration forms for those planning to testify must be submitted by July 22.

The agency will review public comments before determining whether to finalize the proposed revisions.

The TDUSA editorial team creates practical, driver-focused content covering trucking news, industry updates, safety, regulations, and career information for professional truck drivers across the United States. Each article is built to reflect real-world experience, industry developments, and information drivers can use on and off the road.

Last Updated: July 21, 2026

Source: Land Line Media

The post EPA Seeks Public Input on Proposed Changes to 2027 Truck Emissions Rule appeared first on Truck Drivers USA.