August 11, 2022 Update: EMA Withdraws CARB Emissions Challenge
EMA Lawsuit: CARB Emissions Rule Violates Clean Air Act
The Truck and Engine Manufacturers Association said the California Air Resources Board's new emissions regulations don't give manufacturers enough time to comply.

More than half of the commercial vehicles on the road in the U.S. are advanced clean-diesel technology models, according to the Diesel Technology Forum.
Photo: Diesel Technology Forum
The Truck and Engine Manufacturers Association has sued the California Air Resources Board, saying the agency has not provided enough lead time for truck and engine makers to meet its latest emission standards due to go into effect in 2024.
On Dec. 22, 2021, CARB adopted the Heavy-Duty Engine and Vehicle Omnibus Regulation, a package of stringent emission standards, test procedures, and other emission-related requirements applicable to new heavy-duty on-highway engines and vehicles sold in California.
The Omnibus Regulation requires heavy-duty engine and vehicle manufacturers to comply with the new standards on Jan. 1, 2024, giving manufacturers only two years of lead time.
The federal Clean Air Act allows California to establish its own emissions standards, EMA said, provided California meets certain requirements — including providing heavy-duty on-highway engine and vehicle manufacturers four full model years of lead time.
In its filing, EMA said the Omnibus Regulations would require, among other things, that heavy-duty engine manufacturers:
Develop and deploy new technology to reduce nitrogen oxide (NOx) emissions initially by 75% and particulate emissions by 50%.
Demonstrate emissions compliance on entirely new test cycles.
Ensure emissions compliance for certain “Class 3” heavy-duty engines using new durability test procedures out to an extended “useful life” range of 150,000 miles instead of 120,000 miles.
It would require engine manufacturers to redesign, test and build their engines to comply with all of those new requirements starting with Model Year 2024, which begins, at the latest, on Jan. 1, 2024.
“Truck and engine manufacturers are proud that today’s modern engines reduce harmful emissions to near zero levels, and we are committed to building still cleaner products,” said EMA President Jed Mandel in a news release.
“But CARB must provide manufacturers the minimum four years of lead time mandated by Congress…. This lawsuit is simply to ensure that CARB follows all of the prescribed rules — one of which is intended to maximize the likelihood of the smooth and successful implementation of new emission standards.”
Environmental Groups: ‘A New Low’
Environmental groups were quick to criticize the suit. They claim that truck and engine makers that are part of EMA are being hypocrites, as several prominent executives have publicly called for faster action to meet global emissions targets.
A blog post on the website of the Natural Resources Defense Council characterized the action in a headline, “Truck Manufacturers Sue to Continue Polluting,” accompanied by a photo of an old rig belching black smoke in 2014.
“EMA’s lawsuit is a direct attack on our communities, lungs, and the environment,” wrote Patricio Portillo, senior advocate for NRDC’s Climate & Clean Energy Program. “It’s also a new low for EMA, a trade association comprised of vehicle and engine manufacturers who have made public statements about their desire to clean up vehicle pollution….
"This lawsuit is evidence that no matter the public statements, truck manufacturers will never clean up their act unless forced to by vehicle emission standards.”
In an email, a spokesperson representing a group environmental organizations, including NRDC, said, “These standards will literally save lives. American Lung Association's latest State of the Air report finds that California cities continue to top the country's list of most polluted. Diesel death zones situated arounds ports and warehouses are some of the clearest examples of environmental racism in the state thanks to decades of redlining. These communities are desperate for relief.
“Adding insult to injury, California gives EMA members — e.g. Volvo, Daimler, Cummins — hundreds of millions of dollars to support clean truck R&D.”
Other groups represented by this email in addition to NRDC include the Center for Community Action and Environmental Justice, the People's Collective for Environmental Justice, East Yard Communities for Environmental Justice, Central California Asthma Collaborative, BlueGreen Alliance, and Earthjustice’s Right to Zero campaign.
For more on diesel emissions:
More Equipment

Kodiak Lines Up Fleets for Driverless Trucking
An agreement for 75 trucks, a new Texas freight lane, and progress on safety validation move Kodiak closer to its planned driverless highway launch.
Read More →
How GP Transco Builds Fuel Savings a Fraction at a Time
Aerodynamic specs, solar panels, and driver incentives help GP Transco turn small efficiency gains into savings it can reinvest in its people.
Read More →
More Trailer Data Through the Same Seven-Way [Video]
Can trucking’s standard seven-way connector handle more cameras and trailer data? Grote’s Adam Slade shows HDT how the company is using new technology with its 4See trailer system, not only to add a new backup camera but also to expand other capabilities — without adding another connection.
Read More →
Grote: More Cameras, Same Seven-Way Connector
The next-generation 4See rear-view backup camera from Grote uses the standard seven-way connector and supports additional cameras and other trailer data.
Read More →
Trucks at ATA's 2026 MC&E in Charlotte, North Carolina [Photos]
From rigs decked out in patriotic America's 250 paint schemes to autonomous trucks and more, check out these photos from ATA's 2026 Management Conference & Exhibition.
Read More →
Help HDT Find Trucking’s Top Products
Have you come across a new product that could make a difference for trucking fleets? Nominate it for HDT’s 2027 Top 20 Products Awards by November 9.
Read More →
Volvo Unveils New VNX Heavy-Haul and Vocational Truck
Volvo Trucks has launched the VNX, a new vocational truck also available as a tractor in day cab and two sleeper configurations, with one heavy-haul model. The Volvo VNX is powered by Volvo's D13 platform, which delivers up to 540 horsepower and 1,950 pound-feet of torque and is EPA 2027-compliant.
Read More →How GP Transco Cuts Trucking Fuel Costs, a Tenth of a Gallon at a Time
What’s another tenth of a mile per gallon worth? GP Transco shares how equipment upgrades and driver coaching turn small gains into meaningful fuel savings.
Read More →
Electric Yard Tractors Move Beyond Pilots
Operating-cost savings have overtaken sustainability goals as the leading reason surveyed fleets are adopting battery-electric terminal tractors, according to new NACFE research.
Read More →
Continental Introduces New Regional Truck Tires
Continental says its new Generation 5 steer and drive tires for regional operations offer longer tread life, with estimated mileage gains of 22% and 19%, respectively.
Read More →
