  We show that, along the critical isobar, the complete scaling results in a
unique leading scaling qualitatively distinct to that arising from the simple
and the revised scalings. This is verified by a complete-field finite-time
scaling theory, which combines the complete scaling with finite-time scaling,
and its application to the molecular dynamics simulations of the vapor-liquid
critical point of a three-dimensional one-component Lennard-Jones fluid in an
isobaric-isothermal ensemble with linear heating or cooling. Both the static
and the dynamic critical exponents as well as the critical parameters can be
estimated without \emph{a priori} knowledge of the universality class. The
results agree with extant values and thus show the necessity of the complete
scaling to the leading asymptotic behavior along the critical isobar even for
the LJ fluid whose asymmetry is thought to be weak.
