Fuelirium is an acute and relatively sudden decline in attention-focus, perception, and cognition while driving due to overfocus on increasing one's gas mileage. Unlike an aggressive driver or trafficneer, a driver who is in a full fuelirium is oblivious to anyone and anything around him or her including life threatening traffic factors.
That guy is going pretty slow on a crowded interstate what the hell is he doing?! Looks like he's coasting down the hill to save gas!!! A normal fuelirium can be broken by other drivers hitting their horns in unison, a full-blown fuelirium can't be broken even by the cops!