  With the purpose of assessing classic spectroscopic methods on
high-resolution and high signal-to-noise ratio spectra in the near-infrared
wavelength region, we selected a sample of 65 F-, G-, and K-type stars observed
with CARMENES, the new, ultra-stable, double-channel spectrograph at the 3.5 m
Calar Alto telescope. We computed their stellar atmospheric parameters ($T_{\rm
eff}$, $\log{g}$, $\xi$, and [Fe/H]) by means of the StePar code, a Python
implementation of the equivalent width method that employs the 2017 version of
the MOOG code and a grid of MARCS model atmospheres. We compiled four Fe I and
Fe II line lists suited to metal-rich dwarfs, metal-poor dwarfs, metal-rich
giants, and metal-poor giants that cover the wavelength range from 5300 to
17100 angstroms, thus substantially increasing the number of identified Fe I
and Fe II lines up to 653 and 23, respectively. We examined the impact of the
near-infrared Fe I and Fe II lines upon our parameter determinations after an
exhaustive literature search, placing special emphasis on the 14 $Gaia$
benchmark stars contained in our sample. Even though our parameter
determinations remain in good agreement with the literature values, the
increase in the number of Fe I and Fe II lines when the near-infrared region is
taken into account reveals a deeper $T_{\rm eff}$ scale that might stem from a
higher sensitivity of the near-infrared lines to $T_{\rm eff}$.
