a boiling point of less than about about 600 C., preferably less than about 525??? C., and more preferably less than about 500??? C.; an API gravity of at least about 12???, and preferably greater than about 17??? (where API gravity=[141.5/specific gravity]???131.5; the higher the API gravity, the lighter the compound); greatly reduce metals content, including V and NI; greatly reduced viscosity l