  As part of a reanalysis of Galactic Asymptotic Giant Branch stars (hereafter
AGB stars) at infrared wavelengths, we discuss here two samples (the first of
carbon-rich stars, the second of S stars) for which photometry in the near- and
mid-IR and distance estimates are available. Whenever possible we searched also
for mass-loss rates. The observed spectral energy distributions extended in all
cases up to 20 $\mu$m and for the best-observed sources up to 45 $\mu$m. The
wide wavelength coverage allows us to obtain reliable bolometric corrections,
and hence bolometric magnitudes. We show that mid-IR fluxes are crucial for
estimating bolometric magnitudes for stars with dusty envelopes and that the
so-called luminosity problem of C stars (i.e. the suggestion that they are less
luminous than predicted by models) does not appear to exist.
