This week I wrote about the chemical in tires that has been killing the Coho salmon in Puget Sound streams. When there is heavy rain or runoff (quite a common occurrence in the Pacific Northwest) huge fish kills from leaching tire particulate chemicals were found to be devastating to salmon stocks.
All vehicles electric or not have tires, and this adds one more reason to look at travelling smarter and not so intensively by private automobile. Ian Fisher notes that electric cars with their greater mass (battery packs) and high performance wear down tires faster than fuel pumped tire vehicles, showing once more that automobile dependency, of any kind, seems to be environmentally incompatible.
Ian referenced this article from Green Car Reports that shows that tire and brake wear will probably be next for emissions testing, since Emissions Analytics have found that particulate matter tire wear can be “1,000 times worse” than from internal combustion engined vehicles. Particulate is defined as the solid matter shed by vehicles, different from vehicle exhaust gases.
In a study, Emissions Analytics looked at a popular family car with well inflated tires. The study found the vehicle’s tires “emitted 5.8 grams of particulate matter per kilometer, compared to 4.5 milligrams per kilometer from the exhaust. That translates into a tire-wear emissions higher than exhaust emissions by a “factor of 1,000”.
While regenerative braking on electric vehicles results in drivers not having to pump mechanical brakes as much as in gasoline powered vehicles, the weight of battery packs adds onto tire wear, especially with the larger and heavier SUVs.
Emissions Analytics hopes to start an independent emissions agency which could test for vehicle emissions. Sadly only one vehicle manufacturer, General Motors has been interested in adopting a greener tire standard, suggesting that an independent agency will be required to get other vehicle manufacturers on board.
Yesterday the OECD had a webinar panel on the subject of non-exhaust particulate emissions from roads. Some of the methodology used to look at tire wear is particularly interesting, and you can take a look at the panel discussion in the YouTube video below.
Double check that 5.8 grams per km per car number. After 8000 km, you’d be riding on your rims. An average passenger car tire sheds 2.9 kg over a life of 40,000 km, about 0.29 grams per km for an average car (.0725gm per tire per km). That’s 1/20th of the 5.8 grams stated.