Want to add: While "rolling coal" is definitely emission bypass, not all emission bypass is as obvious as "rolling coal" Virtually all the trucks on the way t

Want to add: While "rolling coal" is definitely emission bypass, not all emission bypass is as obvious as "rolling coal" Virtually all the trucks on the way to the local construction sites here each morning very obviously are using some kind of defeat either improve mpg or just be "tough guy" with a louder exhaust - they aren't billowing smoke, but definitely smell/sound way worse than a stock truck Imagine if there are a million trucks on the road right now with those bypass and they put out twenty times the pollution of a stock truck. Destruction spread out so it's not obvious but adds up fast.