  Using the Zaragoza proposal for lattice chiral gauge fermions, the S, U and
\Delta\rho parameters have been calculated at one loop. It is shown that the
continuum values for these quantities can be reproduced without requiring
explicit fine tuning of counterterms. Furthermore, fermion fields doubling is
not necessary. To the best of our knowledge, the Zaragoza proposal is the only
scheme which has these properties. A necessary (although not sufficient)
symmetry is found to support the calculations. Previous results for some of
these parameters in other lattice chiral regularizations are revisited in the
light of this symmetry.
