WASHINGTON, March 29 (Reuters) -

The U.S. government said on Friday it was finalizing tighter

tailpipe emissions standards for heavy duty vehicles like

semi-trucks and buses, but the new rules would not be as strict

as initially proposed in 2023.

The Environmental Protection Agency (EPA) said the new rules

setting standards for the 2027 through 2032 model years will

avoid 1 billion tons of greenhouse gas emissions through 2055

and provide $13 billion in annualized net benefits to society.

In contrast, the EPA had said its tougher proposed rules last

year would have prevented 1.8 billion tons of emissions.

The new standards apply to delivery trucks, garbage

trucks, public utility trucks, transit, shuttle, and school

buses and tractor-trailer trucks.

The final standards tighten requirements at a slower

pace and delay the start of new rules for day cab tractors and

some heavy-duty vocational vehicles, the EPA said.

Heavy duty vehicles account for 25% of all greenhouse gas

emissions from the transportation sector, which accounts for 29%

of U.S. greenhouse gas emissions.

The EPA said the standards "are technology-neutral and

performance-based, allowing each manufacturer to choose what set

of emissions control technologies is best suited for them and

the needs of their customers."

The final rule includes lower electric vehicle projected

sales rates for model years 2027-2029 than the original proposed

rule would have required. But an industry group argued the rule

was still too strict.

The Truck and Engine Manufacturers Association, which

represents Daimler Truck; Volvo Trucks, Cummins

and others, said it was concerned "the final rule will

end up being the most challenging, costly and potentially

disruptive heavy-duty emissions rule in history."

The association added the new rules set a percentage of

zero-emissions vehicles such as fuel cell-powered or electric

vehicles that a company must sell, "which is beyond their own

ability to control."

Tesla

, some Democrats and environmental groups had urged

the EPA to adopt even tougher rules.

Abigail Dillen, president of the Earthjustice

environmental group, said Friday "the EPA did not go far enough

to protect communities from dangerous health impacts linked to

heavy-duty truck pollution" and added "truck manufacturers have

pushed EPA to slow-walk this change."

The American Trucking Associations said targets beyond 2030

"remain entirely unachievable given the current state of

zero-emission technology, the lack of charging infrastructure

and restrictions on the power grid."

Current tailpipe emissions limits for heavy duty trucks

and engines were set in 2016 covering the 2021 through 2027

model years.

The Sierra Club's Katherine García praised the new EPA

rules adding "it's crucial that truck manufacturers get into the

fast lane with zero-emission trucks to deliver the climate,

health, and economic benefits we deserve."

Last week, the EPA finalized emissions rules for light and

medium duty vehicles through 2032, cutting its target for U.S.

electric vehicle adoption from 67% by 2032 to as little as 35%.