Rolling coal is the practice of tampering with a vehicle’s emissions control system, causing it to spew black clouds of sooty exhaust.

  • @Meanshadows35
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    -21 year ago

    Fuel efficiency yes. These newer diesel motors go into dpf mode around 300 miles to burn off any diesel soot. Which in turn uses more diesel and tanks the fuel economy. I get why some guys do it especially when the egr system goes up. But rolling coal is fucking stupid. Terrible on the motor too.