Rolling coal is the practice of modifying a diesel engine to emit large amounts of black or grey sooty exhaust fumes—diesel fuel that has not undergone complete combustion. It is a predominantly North American phenomenon (more specifically in the United States and Canada), despite being illegal.
Rolling coal is the practice of modifying a diesel engine to emit large amounts of black or grey sooty exhaust fumes—diesel fuel that has not undergone complete combustion. It is a predominantly North American phenomenon (more specifically in the United States and Canada), despite being illegal.
https://en.wikipedia.org/wiki/Rolling_coal