U.S. EPA proposes its strictest-ever vehicle emissions limits for 2027-32

WASHINGTON — The U.S. Environmental Protection Agency on Wednesday unveiled its strictest-ever limits on vehicle tailpipe pollution, a regulatory move that could spur greater sales of electric vehicles in the United States.

The proposed vehicle emissions standards cover the 2027-32 model years for light- and medium-duty vehicles and — coupled with federal incentives and other investments — could accelerate an ongoing transition to EVs while clamping down on harmful pollutants in the transportation sector, the nation's largest source of greenhouse gas emissions and a main cause of air pollution.

Under the proposal, EVs could make up 67 per cent of new light-duty vehicle sales and 46 per cent of medium-duty vehicle sales in the 2032 model year, according to EPA projections.

"By proposing the most ambitious pollution standards ever for cars and trucks, we are delivering on the Biden-Harris administration's promise to protect people and the planet, securing critical reductions in dangerous air and climate pollution and ensuring significant economic benefits like lower fuel and maintenance costs for families," EPA Administrator Michael Regan said in a statement.

"These ambitious standards are readily achievable thanks to President Biden's 'Investing in America' agenda, which is already driving historic progress to build more American-made electric cars and secure America's global competitiveness," he added.

For the 2027-32 model years, the EPA said its proposed standards are expected to save consumers $12,000 (all figures in USD) over the lifetime of a light-duty vehicle compared with a vehicle not subject to the new tailpipe pollution limits.

For light-duty vehicles, the emissions standards would increase in stringency each year, resulting in a fleetwide average target of 82 grams per mile (1.6 kilometres) of carbon dioxide in the 2032 model year.

For medium-duty vehicles, the standards also increase in stringency and are projected to result in an average target of 275 grams per mile (1.6 km) of CO2 by the 2032 model year.

The proposal would require a combined fleet year-over-year CO2 reduction of 18 per cent in the 2027 model year; 13 per cent in 2028; 15 per cent in 2029; 8 per cent in 2030; 9 per cent in 2031; and 11 per cent in 2032. That equates to a combined fleet average year-over-year CO2 reduction of 13 per cent.

In comparison, under the rule for 2023-26 model-year vehicles, emissions standards increase in stringency between about 5 and 10 per cent each model year. The standards mandate an industrywide target of 161 grams of carbon dioxide per mile (1.6 km) — or 40 mpg (5.88 L/100 km) on window stickers — by the 2026 model year.

The EPA said its proposed light-duty standards in the 2032 model year could lead to a 56 per cent reduction in projected fleetwide average greenhouse gas emissions target levels compared with the 2026 model year standards. For the medium-duty standards, the reduction is projected to be 44 per cent.

The proposal for light- and medium-duty vehicles also is expected to prevent 7.3 billion tons of carbon dioxide emissions through 2055, "equivalent to eliminating all greenhouse gas emissions from the entire current U.S. transportation sector for four years," the agency said.

While the light-duty standards continue to be footprint based, the EPA is proposing to revise the vehicle footprint curves "to flatten the slope of each curve and to narrow the numerical stringency difference between the car and truck curves," according to the proposal.

It is also proposing to revise certain compliance flexibilities, including fully phasing out the off-cycle credits program by the 2031 model year and limiting eligibility only to internal combustion engine vehicles.

Also on Wednesday, the EPA issued its "Phase 3" proposed greenhouse gas standards for heavy-duty vocational vehicles, such as delivery trucks and school buses, that complement criteria pollutant standards finalized in December. That rule covers the 2028-32 model years and revises certain standards for the 2027 model year that were established in a "Phase 2" rule.

Through 2055, the EPA projects the proposed standards for light-, medium- and heavy-duty vehicles would prevent nearly 10 billion tons of CO2 emissions.

The EPA's new proposed limits on tailpipe pollution, if finalized, could help President Joe Biden's goal for half of all new vehicles sold in the U.S. to be zero emission — battery-electric, plug-in hybrid and fuel cell — in 2030.

The plan also is key to U.S. commitments on reducing emissions by at least 50 per cent below 2005 levels by mid-decade, reaching 100 per cent carbon pollution-free electricity by 2035 and achieving net-zero emissions economywide by 2050.

To be sure, neither Biden nor his administration has called for a ban on sales of new combustion-engine vehicles by a certain date — actions that are underway in places such as California and the European Union.

For the U.S. auto industry, the EPA's vehicle emission rules could be a major regulatory push — and challenge — to speed electrification plans.

In a blog post Wednesday, Alliance for Automotive Innovation CEO John Bozzella called the EPA's proposal "aggressive by any measure."

"By that I mean it sets automotive electrification goals in the next few years that are … very high," he wrote, noting that the proposal exceeds both Biden's 50 per cent ZEV sales target and another goal outlined in a governmentwide transportation decarbonization plan.

"How will EPA justify exceeding the carefully considered and data-driven goal announced by the administration in the executive order and the more recent national blueprint?" Bozzella asked. "That's a key question as the rulemaking unfolds and something to look for in the expansive proposal."

Automakers already will have invested $1.2 trillion in electrification by 2030, according to the alliance, which represents many of the automakers aiming for between 40 and 50 per cent U.S. sales of ZEVs in that time frame.

"Even with positive EV sales momentum and product excitement, there are challenges to the electrification transition ahead. This requires a massive, 100-year change to the U.S. industrial base and the way Americans drive," the group said in an April 6 memo.

The alliance said achieving the EPA's proposed rules will be tied to "supportive public policies and favorable market conditions," notably EV charging infrastructure, vehicle affordability and access to critical minerals.

"Regulatory mandates alone will not drive the conditions … that will determine the ultimate success of the EV transition," the group said.