  We present a systematic analysis of the quasielastic scaling functions
computed within the Relativistic Mean Field (RMF) Theory and we propose an
extension of the SuperScaling Approach (SuSA) model based on these results. The
main aim of this work is to develop a realistic and accurate phenomenological
model (SuSAv2), which incorporates the different RMF effects in the
longitudinal and transverse nuclear responses, as well as in the isovector and
isoscalar channels. This provides a complete set of reference scaling functions
to describe in a consistent way both $(e, e')$ processes and the
neutrino/antineutrino-nucleus reactions in the quasielastic region. A
comparison of the model predictions with electron and neutrino scattering data
is presented.
