According to new research, a regulatory gap allows automakers like Ford and BMW to make US cars that emit more ultrafine particles that harm human health than equivalent models sold in Europe and other markets.
British testing specialist, Emissions Analytics, took four pairs of cars – from Ford, BMW, Toyota and Stellantis – and compared the impact of tailpipe filters that are widely used in Europe. Regulations limit the number of harmful particles that vehicles can emit, but not in the United States, where the same rules do not apply.
China and India use similar standards to Europe.
According to industry estimates, a gasoline particulate filter costs carmakers around $200.
Emissions Analytics estimated around 300 million gasoline-powered internal combustion engine (ICE) vehicles travelling 10,000 miles annually on U.S. roads for the next decade will unnecessarily emit 1.6 septillion (1,600,000,000,000,000,000,000,000) harmful particles.
‘Few things in emissions control are a no-brainer,’ said Emissions Analytics CEO Nick Molden. ‘In this case, the benefits appear high, costs relatively low, and risk minimal.’
The research found in a cold start in an urban area, the average European model, emitted 83.7% fewer particles than its US counterpart.
Emissions Analytics said the most significant difference was in the Ford Kuga, which consistently emitted 95% fewer harmful particles than its US sibling, the Ford Escape, and 96% in a warm highway start.
The research also found significant differences between the BMW X5, Stellantis’s Jeep Wrangler, and the Toyota RAV4.
Ford, BMW, Stellantis and Toyota said they build their vehicles to meet all local regulations and emphasised they will spend tens of billions of dollars switching to zero-emission electric vehicles.
‘Every BMW vehicle sold in the US either meets or exceeds the US requirements for vehicles in this market,’ BMW said.
The filters are used on both diesel and gasoline vehicles across markets and are fitted on US diesel vehicles, usually producing bigger, heavier particles.
But the gasoline vehicles Emissions Analytics tested in the United States have been assumed to meet standards set by the US regulator, the Environmental Protection Agency (EPA), without requiring a filter.
Since the US regulation was introduced in 2014, industry experts say that direct injection fuel technology, which improves fuel efficiency, has increased the amount of particulate matter gasoline cars emit.
Ultrafine particles are harmful because their microscopic size means they can be drawn deep into human lungs.
Even under the most aggressive US scenarios for phasing out ICEs, they will likely be sold into the 2030s.
‘There is a strong argument we should do what we can to make ICE vehicles as clean as possible, whatever the speed of electrification,’ Molden said.
Allen Schaeffer, executive director at the Diesel Technology Forum, estimated gasoline direct injection vehicles accounted for about half of North American vehicle sales.
In emailed comments, the EPA said carmakers had met its standards without needing filters, but it is looking at filters and other technologies for new rules from 2027.
‘We hope to continue incentivising stricter emissions standards for vehicles going forward,’ the agency said.
