Rolling Coal aka Spraying Prius Repellent is the illegal practice of injecting additional fuel into a diesel engine with the intention of creating a large cloud of black smoke. Truck lovers have been doing it for years, but recently liberals have taken notice and are trying to outlaw the practice. Some people use rolling coal to show off their engine's power, others to spray down attractive women with soot, but the main use these days is to annoy liberals who are worried about the lie of global warming. Renegade patriots are now using the practice to protest liberal encroachments on freedom.
How it works
Normally diesel engines are designed to make little soot, but through engineering this can be changed. A switch is installed to inject extra fuel into the engine which is incompletely combusted leaving a large quantity of thick sooty black smoke to be blown out of the exhaust. Owners generally install custom exhausts or stacks, sometimes moving the outlet to the bed of the truck in a manner similar to an 18 wheeler. Cummins and Powerstroke diesels are the best, but it works on Duramaxs pretty well too.