Vigilante 8 is a vehicular-combat game set in an alternate 1975. Australian terrorist Sid Burn is hired by OMAR to dispose of all competing oil companies in the U. S. so that OMAR can establish an oil monopoly in the country. After hearing reports of destruction by Sid Burn's gang, the Coyotes, a man named Convoy, a kind-hearted trucker, forms a group of his own, the Vigilantes, to combat the Coyotes and stop the tyranny of OMAR.

The game's storyline is built around an alternate history, in which there was a worldwide oil crisis in the 1970s and the U. S. was on the verge of an economic breakdown. Strikes, riots and crime were rampant, and all available law enforcement were brought to the cities leaving the outlands vulnerable. A foreign multinational oil consortium, Oil Monopoly Alliance Regime (OMAR), was determined to monopolize the world oil trade. The U. S. was the last country that stood in their way and they were prepared to go to any length to bring the U. S. to its knees. OMAR hired Sid Burn, a professional terrorist, to push the U. S. economy over the edge. Sid began to organize his troops in the remote areas of the southwest. Calling themselves the "Coyotes," they began to target oil refineries, commercial installations and other vital industry throughout the region. With the law enforcement in the cities, some desperate civilians began to take the law into their own hands. Led by a trucker named Convoy and referred to simply as the "Vigilantes," this oddball group soon became a major hindrance to Sid. Meanwhile, the U. S. government, feeling more vulnerable than ever, was intensifying its research and development of a new military arsenal. The most advanced weaponry, rumored to be based on UFO technology, was located at Site-4, a secret facility at Papoose Lake. This information was not lost on Sid, and the Coyotes ambushed the facility. However the Vigilantes unexpectedly appeared to stop them and as a result, both parties found themselves in possession of the world's most advanced weaponry. What followed were no ordinary skirmishes. Auto clashes ensued all over the land, from Colorado's Rockies to California's farmlands, only to culminate in a battle like no other. To this day the events which took place are only a matter of speculation.