Tire Wear Emissions 1000 Times More Than Exhaust Emissions

Pollution from tire wear can be 1,000 times worse than what comes out of a car’s exhaust, European consultancy Emissions Analytics has found. Regulation of exhaust emissions by the EU results in  new cars that emit little particle pollution. However, unregulated tire wear pollution can be 1,000 times worse, finds independent real-world testing experts at Emissions Analytics. It says that the increased popularity of SUVs, larger and heavier than standard vehicles, exacerbates this problem – as does growing sales of heavy EVs and widespread use of budget tires.

Non-exhaust emissions (NEE) are particles released into the air from brake wear, tire wear, road surface wear and re-suspension of road dust during  vehicle operation. No legislation is in place to limit or reduce NEE, but they affect air quality.

NEEs are currently believed to constitute the majority of primary particulate matter from road transport, 60% of PM2.5 and 73% of PM10. In its 2019 report ‘Non-Exhaust Emissions from Road Traffic’ by the UK Government’s Air Quality Expert Group (AQEG), it recommended that NEE are immediately recognized as a source of ambient concentrations of airborne particulate matter, even for vehicles with zero exhaust emissions of particles – such as EVs.

Emissions Analytics – an independent global testing and data specialist for the measurement of real-world emissions – performed some initial tire wear testing. Using a popular family hatchback running on brand new, correctly inflated tires, it says that the car emitted 5.8 grams per kilometer of particles.

Compared with regulated exhaust emission limits of 4.5 milligrams per kilometer, the completely unregulated tire wear emission is higher by a factor of over 1,000. Emissions Analytics notes that this could be even higher if the vehicle had tires which were underinflated, or the road surfaces used for the test were rougher, or the tires used were from a budget range.

Richard Lofthouse, Senior Researcher at Emissions Analytics said: “It’s time to consider not just what comes out of a car’s exhaust pipe but particle pollution from tire and brake wear. Our initial tests reveal that there can be a shocking amount of particle pollution from tires – 1,000 times worse than emissions from a car’s exhaust.

“What is even more frightening is that while exhaust emissions have been tightly regulated for many years, tire wear is totally unregulated – and with the increasing growth in sales of heavier SUVs and battery-powered electric cars, non-exhaust emissions (NEE) are a very serious problem.”

Nick Molden, CEO of Emissions Analytics said: “The challenge to the industry and regulators is an almost complete black hole of consumer information, undone by frankly out of date regulations still preoccupied with exhaust emissions. In the short term, fitting higher quality tires is one way to reduce these NEEs and to always have tires inflated to the correct level.