  The critical point affects the coexistence behavior of the vapor-liquid
equilibrium densities. The length of the critical influence zone is under
debate because for some properties, like shear viscosity, the extension is only
a few degrees, while for others, such as the density order parameter, the
critical influence zone range covers up to hundreds of degrees below the
critical temperature. Here we show that for a simple molecular potential of
ethane, the critical influence zone covers a wide zone of tens of degrees
(below the critical temperature) down to a transition temperature, at which the
apparent critical influence zone vanishes and the transition temperature can be
predicted through a pressure analysis of the coexisting bulk liquid phase. The
liquid phases within the apparent critical influence zone show low densities,
making them behave internally like their corresponding vapor phases. Therefore,
the experimentally observed wide extension of the critical influence zone is
due to a vapor-like effect due to low bulk liquid phase densities.
