> Why is it ever different between winter and summer? Here in Oslo it's due to the local air pollution caused by winter tires. Studded tires especially but non

> Why is it ever different between winter and summer? Here in Oslo it's due to the local air pollution caused by winter tires. Studded tires especially but non-studded as well as they have soft rubber which sheds particulates more easily. Due to physics, cold air can act as a lid, preventing the ground-level air from getting refreshed, causing a build-up of particulates. Lower speed means less particulates from the asphalt and rubber.