A coalroller is typically a truck that spews black smoke out of (usually a smokestack like on semis) it's exhaust under the guise of a backwater hick saying, " it's the diesel that does it!" Like the word suggests, it's not actually diesel that causes this black death cloud; it is, in fact, coal dust.
"Yo Jack, is there a house on fire here?"
"No, Jim. It's some asshole driving his coalroller down the road."
"No, Jim. It's some asshole driving his coalroller down the road."
by Christian98 April 22, 2015