Tires on EVs, unfortunately, still produce emissions, which in turn makes zero-emissions cars not truly emissions-free. Thankfully, a London-based startup called The Tyre Collective may have found a way to cut down on this unseen pollution.

As vehicles drive along roads, tiny bits of the wheels pill and scatter over the asphalt. To add to this, the main ingredient in rubber tires isn’t even rubber. Instead, it’s a concoction of harmful substances that are mixed together to create the material. As the tires shed on the road, these little pieces will ultimately find their way into waterways, soil, and the air around us.

A road test conducted by the research organization Emissions Analytics showed that a gas-powered car sheds 73 milligrams of tires per 0.6 miles, while an EV sheds 15 milligrams more for the same distance. This is due to the fact that electric cars often weigh more than traditional cars do thanks to their batteries.