  We make rotation curve fits to test the superfluid dark matter model. In
addition to verifying that the resulting fits match the rotation curve data
reasonably well, we aim to evaluate how satisfactory they are with respect to
two criteria, namely, how reasonable the resulting stellar mass-to-light ratios
are and whether the fits end up in the regime of superfluid dark matter where
the model resembles modified Newtonian dynamics (MOND). We fitted the
superfluid dark matter model to the rotation curves of 169 galaxies in the
SPARC sample. We found that the mass-to-light ratios obtained with superfluid
dark matter are generally acceptable in terms of stellar populations. However,
the best-fit mass-to-light ratios have an unnatural dependence on the size of
the galaxy in that giant galaxies have systematically lower mass-to-light
ratios than dwarf galaxies. A second finding is that the superfluid often fits
the rotation curves best in the regime where the superfluid's force cannot
resemble that of MOND without adjusting a boundary condition separately for
each galaxy. In that case, we can no longer expect superfluid dark matter to
reproduce the phenomenologically observed scaling relations that make MOND
appealing. If, on the other hand, we consider only solutions whose force
approximates MOND well, then the total mass of the superfluid is in tension
with gravitational lensing data. We conclude that even the best fits with
superfluid dark matter are still unsatisfactory for two reasons. First, the
resulting stellar mass-to-light ratios show an unnatural trend with galaxy
size. Second, the fits do not end up in the regime that automatically resembles
MOND, and if we force the fits to do so, the total dark matter mass is in
tension with strong lensing data.
