  We present a numerical analysis of the validity of classical and generalized
hydrodynamics for Lattice Boltzmann Equation (LBE) and Lattice BGK methods in
two and three dimensions, as a function of the collision parameters of these
models. Our analysis is based on the wave-number dependence of the evolution
operator. Good ranges of validity are found for BGK models as long as the
relaxation time is chosen smaller than or equal to unity. The additional
freedom in the choice of collision parameters for LBE models does not seem to
give significant improvement.
