well, the rubber compounds used are very different too. You would not enjoy riding a bicycle on the hard rubber used for a semi-truck tire. The 4th-power rule

well, the rubber compounds used are very different too. You would not enjoy riding a bicycle on the hard rubber used for a semi-truck tire. The 4th-power rule is more applicable when it comes to road damage. If you want a comparative analysis of tire wear and environmental impact, you have to consider the average mileage before a tire is worn out, the volume/mass of material that's lost, etc. This article[0] suggests 150,000 miles for steer tires, and 300-500k for drive tires. If a tire starts out at 1/2" (16/32") and is worn down to 3/32", a delta of 13/32" or ~10mm. Radius of a typical 22.5" tire is 500mm and tread width 250mm, so you have (π500^2-π490^2)*250mm = 7.5L of rubber material deposited all over the world for each tire. Over 1M miles, this is 12 steer tires, and 24 drive tires, so ~200L of tire rubber over a typical semi truck lifetime. 0 - https://www.fleetowner.com/operations/article/21676805/tires-closing-the-gap https://www.fleetowner.com/operations/article/21676805/tires...