Rolling coal is the practice of tampering with a vehicle’s emissions control system, causing it to spew black clouds of sooty exhaust.
Rolling coal is the practice of tampering with a vehicle’s emissions control system, causing it to spew black clouds of sooty exhaust.
Those types of tuners also exist, and depending on the tune they can actually in some cases slightly improve fuel economy (depending on driving style). I tuned my Audi A3 to “Stage 1+” and actually have seen slightly better fuel economy doing highway driving to which I attribute the new ECU/TCU tunes allowing me to stay in gear longer during acceleration I guess?