Heavy Duty Trucking Logo
MenuMENU
SearchSEARCH

Stricter Truck Emissions Standards are a Gorilla of a Monkey Wrench [Commentary]

CARB may be able to quickly squeeze heavy-truck emission limits yet tighter, explores HDT's Contributing Washington/Business Editor David Cullen in the Passing Zone column.

David Cullen
David Cullen[Former] Business/Washington Contributing Editor
Read David's Posts
March 27, 2023
Stricter Truck Emissions Standards are a Gorilla of a Monkey Wrench [Commentary]

CARB may be able to quickly squeeze heavy-truck emission limits yet tighter, explores HDT's Contributing Washington/Business Editor David Cullen in the Passing Zone column.

Graphic: HDT

3 min to read


If approved, a request by California to enact markedly stricter heavy-truck emissions standards than those set by the federal government will massively disrupt the already-fraught view trucking holds of the upcoming rules laid out by the Environmental Protection Agency.

This gorilla of a monkey wrench will vigorously shake the tightrope of a timeline that truck and engine manufacturers are navigating to ensure compliance with the new regulations while delivering the performance expected by fleets.

Ad Loading...

Disrupting the engineering already in motion by changing the rules this late in the game would ripple down the manufacturing supply chain to gum up the works. That would upset fleet plans to replace old trucks with new in the face of another pre-buy explosion.

It’s not a done deal, but news reports in the general media earlier this month strongly suggested that approval was imminent. Washington Post reporter Anna Phillips is credited with having broken the news on March 20. EPA “intends to grant California ‘waivers’ to enforce environmental rules that are significantly tougher than federal requirements and that state regulators have already approved,” she reported.

But wait, there’s more bad news. Whenever California secures waivers of preemption, per the California Air Resources Board, the federal Clean Air Act “allows other states that are or have been noncompliant with federal ambient air quality standards to adopt California’s standards as their own.”

To date, 13 states and the District of Columbia have adopted all or part of certain California emission standards.

Within three days of the Post story, the American Trucking Associations issued a blistering press release on the waiver request. ATA keyed in on how changing upcoming emissions rules now could derail the supply chain that drives truck production.

Ad Loading...

“Our industry hopes these reports aren’t true,” stated ATA President and CEO Chris Spear. “The state and federal regulators collaborating on this unrealistic patchwork of regulations have no grasp on the real costs of designing, building, manufacturing, and operating the trucks… As we learned in the pandemic, the supply chain can be a fragile thing — and its integrity must be preserved at the national level.”

One day after ATA spoke out, word came that a new advocacy group of trucking stakeholders had been formed to “get to zero emissions in a responsible and feasible manner.” The Clean Freight Coalition consists of motor carriers, truck makers, and truck dealers. Its founding members include ATA, the Truckload Carriers Association, and the Truck & Engine Manufacturers Association (EMA).

The Clean Freight Coalition has twin interrelated goals: Advocate for public policies that transition toward a zero-emission future while assuring “affordable and reliable freight transportation and [protecting] the nation's supply chain.”

Perhaps the launch of CFC stemmed from last summer’s decision by EMA to withdraw its lawsuit against CARB that contended the agency did not provide enough lead time for truck and engine makers to meet its 2024 emission standards.

That EMA legal action had spurred substantial blowback by environmental groups and some of its own members, including Cummins, Ford, and GM, that publicly stated they did not support the litigation. For example, a joint letter sent by 34 regional and national environmental groups upbraided EMA’s member leadership, including the heads of Daimler Truck NA, Navistar, Paccar, and Volvo Group NA, for “harmful EMA lobbying and disinformation campaigns designed to slow or stall the transition to cleaner trucks.”

Ad Loading...

So, it would seem that the further development of engines and trucks to comply with 2024 and 2027 diesel emission standards is not likely to go as anyone has hoped. At this point, whether it will be a race back to the drawing boards or a steady push to the current finish line is anyone’s bet.

This commentary appears in the April 2023 issue of Heavy Duty Trucking.

More from David Cullen's Passing Zone column: M&A in Trucking: A Tale of Two Year

Subscribe to Our Newsletter

More Fuel Smarts

SponsoredFebruary 1, 2026

Stop Watching Footage, Start Driving Results

6 intelligent dashcam tactics to improve safety and boost ROI

Read More →
Fuel Smartsby Deborah LockridgeJanuary 29, 2026

California: Clean Truck Check Rules Still in Force for Out-of-State Trucks, Despite EPA Disapproval

The Environmental Protection Agency said California can’t enforce its Heavy-Duty Inspection and Maintenance Regulation, known as Clean Truck Check, on vehicles registered outside the state. But California said it will keep enforcing the rule.

Read More →
Illustration of Department of Justice building superimposed by truck exhaust stacks
Fuel SmartsJanuary 27, 2026

Justice Department Pulls Back on Criminal Prosecution of Diesel Emissions Deletes

The Trump administration has announced it will no longer criminally prosecute “diesel delete” cases of truck owners altering emissions systems in violation of EPA regulations. What does that mean for heavy-duty fleets?

Read More →
Ad Loading...
HDT Spotlight video on natural gas truck engines.
Fuel Smartsby Jack RobertsJanuary 26, 2026

Why the Cummins X15N Changed the Conversation About Natural Gas Trucking

Natural gas is quietly building a reputation as a clean, affordable, and reliable alternative fuel for long-haul trucks. And Ian MacDonald with Hexagon Agility says the Cummins X15N is a big reason why.

Read More →
Blue Tesla Semi pulling flatbed trailer inside warehouse or manufacturing facility
Fuel SmartsJanuary 21, 2026

First Tesla Semi for RoadOne IntermodaLogistics

RoadOne IntermodaLogistics has bought a fully electric Tesla Semi heavy-duty truck, the first of up to 10 for its Oakland, California, operations.

Read More →
Mercedes-Benz eActros trucks.
Fuel SmartsJanuary 20, 2026

Mercedes-Benz Initiates Megawatt Charging and Long-Haul EV Truck Trials

Mercedes-Benz has begun a new series of tests in Europe to validate vehicle compatibility with megawatt chargers and assess charging performance, thermal management, and usability on long-haul duty routes.

Read More →
Ad Loading...
Windrose-Greenlane truck charging bundle.
Fuel SmartsJanuary 20, 2026

Windrose Bundles Free EV Truck Charging with Greenlane Infrastructure

Windrose customers will receive unlimited charging for three months on Greenlane’s high-power charging network.

Read More →
SponsoredJanuary 19, 2026

3 New Ways Fleet Software Pays: ROI opportunities for modern fleet managers

Safety, uptime, and insurance costs directly impact profitability. This eBook looks at how fleet software is evolving to deliver real ROI through proactive maintenance, AI-powered video telematics, and real-time driver coaching. Learn how fleets are reducing crashes, defending claims, and using integrated data to make smarter operational decisions.

Read More →
SponsoredJanuary 19, 2026

Basic Tracking vs Next Generation Fleet Technology

Fleet software is getting more sophisticated and effective than ever, tying big data models together to transform maintenance, safety, and the value of your existing tech stack. Fleet technology upgrades are undoubtedly an investment, but updated technology can offer a much higher return. Read how upgrading your fleet technology can increase the return on your investment.

Read More →
Ad Loading...
Fuel Smartsby Deborah LockridgeDecember 22, 2025

From Truck APUs to Intelligent Engines: NACFE Updates Idle Reduction Report

Idle reduction for heavy-duty trucks has come a long way. An updated playbook from the North American Council for Freight Efficiency explains what technologies deliver results today — and what’s coming next.

Read More →