  The purpose of this paper is threefold: a) Check if the rather poor Standard
Model (SM) fit to all electroweak data can be improved in its minimal
supersymmetric extension (MSSM); b) Check what constraints present electroweak
data has on the parameter space of the supergravity inspired Constrained MSSM
(CMSSM); c) Check if with the present high precision of the gauge coupling
constants exact gauge coupling unification is still possible. The value of
tan\beta in the CMSSM is constrained to be above 6.5, while the value of the
gaugino masses at the GUT scale has to be above 220 GeV, which corresponds to a
lower limit on the lightest neutralino (chargino) of ca. 95 (175) GeV. It is
shown that the larger values of \alpha_s from R_l and \sinw from A_FB are
consistent with perfect gauge unification. The low \alpha_s value from the
hadronic cross section is correlated with the fact that the number of neutrino
flavours is 2\sigma below the known value of 3 in the SM, which is shown to
correspond to a 3sigma deviation in the hadronic cross section. Lowering
sigma_{had} by 3sigma brings alpha_s up to 0.12 and N_nu up to 3.
