Pollution from Tire Wear is 1,000 Times Worse Than Exhaust Emissions

Want to cut your carbon footprint? Consider using high-quality tires, or at least make sure they’re properly inflated. This conclusion comes from Emissions Analytics, the world’s leading independent specialist for the scientific measurement of real-world emissions.

In their study, they found that non-exhaust emissions generated by tire wear can be 1,000 times worse than what comes out of a car’s exhaust.

Harmful particle matter from tires—and also brakes—is a very serious and growing environmental problem, one that is being exacerbated by the increasing popularity of large, heavy vehicles such as SUVs, and growing demand for electric vehicles, which are heavier than standard cars because of their batteries.

What’s more, vehicle tire wear pollution is completely unregulated, unlike exhaust emissions which have been rapidly reduced by car makers thanks to the pressure placed on them by various governments. New cars now emit very little in the way of particulate matter but there is growing concern around ‘non-exhaust emissions’.

Non-exhaust emissions (NEE) are particles released into the air from brake wear, tire wear, road surface wear, and resuspension of road dust during on-road vehicle usage. No legislation is in place to limit or reduce NEE, but they cause a great deal of concern for air quality.

NEEs are currently believed to constitute the majority of primary particulate matter from road transport, 60 percent of PM2.5 and 73 percent of PM10.

To understand the scale of the problem, Emissions Analytics performed some initial tire wear testing. Using a popular family hatchback running on brand new, correctly inflated tires, they 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 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 – all very recognizable scenarios in ‘real world’ motoring.