Equipment Manufacturers Meeting on CARB Engine Emissions Regulatory Landscape: The Need for Regulatory Certainty

Equipment manufacturing executives met with California Air Resources Board (CARB) leadership in Sacramento on Wednesday for an off-the-record discussion. This followed CARB’s July 2, 2026, approval of $70 million in incentives aimed at cutting emissions from off-road equipment.

Media were not part of that meeting, but the manufacturing executives made themselves available after.

They discussed the need for commonsense, science-based regulations that protect public health and the environment, equipment manufacturers’ investments in emissions-reducing technologies, and the path to achieving emissions reductions at scale.

The Association of Equipment Manufacturers (AEM) hosted a media roundtable to discuss the evolving engine emissions regulatory landscape in California and its impact on equipment manufacturers, equipment operators, and the broader economy.

There was a candid discussion about how manufacturers are working to achieve California’s unique emissions reductions, but also the need for achievable, aligned, and durable regulations that are not tied to a single technology pathway – or dominated by a single state.

The equipment manufacturing executives present at the media roundtable were Bill Hood, Vice President at Weiler, Nicholas Rudowich, Director of State Affairs at the Association of Equipment Manufacturers (AEM), Jamie Rudin, Director of Public Affairs at the Association of Equipment Manufacturers (AEM), Chris Walters, Head of North America Public Affairs at Iveco Group.  Iveco Group is the parent company of FPT Industrial, a manufacturer of diesel and alternative fuel engines.

CARB has a lengthy track record of progressively tighter engine and equipment rules, and it continues to advance new ones that affect manufacturers and agricultural equipment. Rather than letting equipment manufacturers innovate, and through advanced technological improvements, reduce emissions, the CARB keeps reducing emissions requirements – putting the cart before the horse. 

Additionally, real world emissions are where the most improvements are found. CARB uses a laboratory to achieve theirs.

The manufacturers really just want CARB to recognize a realistic real world emission standard.

CARB sets and enforces emission standards for new off-road engines sold or used in California, often exceeding federal EPA rules. making equipment manufacturers jump through ridiculous hoops, or make two sets of everything – one for California and one for the rest of the country.

It is notable that modern engines are extremely efficient, and that includes modern agricultural equipment engines – primarily advanced diesel units in tractors, combines, and related machinery, which are highly efficient for their demanding, variable-load applications.

But that’s all noise to the California Air Resources Board, which has never looked at California’s air quality data and acknowledged that our air is the cleanest in the nation – except when the now-annual wildfires are blazing.

“Objective science on climate has been sacrificed to politics,” said 2022 Nobel Laureate John Clauser, one of 1,600 actual scientists known as the CO2 Coalition, in a 2024 letter to the California Air Resources Board stating that there is “NO Climate Crisis.” “The preeminence of politics is all the worse,” he said, “because so much money has already gone to climate.”

California also has record low levels of air pollution that are below the threshold of human health effects, James E. Enstrom, PhD, MPH has told us repeatedly for years. He’s also one of the 1,600 scientists signed onto the letter to CARB.

The $70 million from the Air Quality Improvement Program, mentioned above, funds the state’s Clean Off-Road Equipment Voucher Incentive Project (CORE). It consists of $35 million from the fiscal year 2025-2026 budget, and another $35 million from the 2026-2027 budget.

According to Dieselnet.com, Tier 4 Final is the current baseline for most new diesel off-road engines.

CARB’s proposed Tier 5 standards for new off-road compression-ignition engines require NOx emissions from off-road engines to be reduced by up to 90%, compared to the current US EPA Tier 4 final standards, while PM emissions would have to be reduced by up to 75%—forcing the use of diesel particulate filters on all affected off-road engines.

Federal Clean Air Act preemption limits CARB’s reach on new engines under 175 hp used in farm or construction equipment.

Manufacturers must get CARB certification, or meet equivalent federal standards where applicable, for engines and equipment sold into California. Because California is a major market, this frequently drives national product designs, after-treatment systems, costs, and complexity.

Notably, the manufacturers said that in Europe, their Tier 5 is more closely aligned with California’s Tier 4.

“California is an outlier – no other state gets into emissions,” said Chris Walters with Iveco. “They adhere to the federal regulations. And, regulatory certainty is critical for manufacturers, as is harmony between states.”

“California is working opposite direction of harmonization inducements.”