Pollution from tyre wear can be 1,000 times worse than what comes out of a car’s exhaust, according to Emissions Analytics, a UK-based firm which specialises in calculating real-world emissions and fuel efficiency for passenger and commercial vehicles.
To understand the scale of the problem, Emissions Analytics performed some initial tyre wear testing. Using a popular family hatchback running on brand new, correctly inflated tyres, it was found 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 tyre wear emission is higher by a factor of over 1,000.
Non-exhaust emissions (NEE) are particles released into the air from brake wear, tyre wear, road surface wear and resuspension of road dust during on-road vehicle usage. It is completely unregulated, unlike exhaust emissions which have been rapidly reduced by car makers thanks to the pressure placed on them by European emissions standards.
NEEs are immediately recognised as a source of ambient concentrations of airborne particulate matter, even for vehicles with zero exhaust emissions of particles – such as EVs. Emissions Analytics notes that this could be even higher if the vehicle had tyres which were underinflated, or the road surfaces used for the test were rougher, or the tyres used were from a budget range – all very recognisable scenarios in ‘real world’ motoring.