  We generalize (linearized) relativistic hydrodynamics by including all order
gradient expansion of the energy momentum tensor, parametrized by four
momenta-dependend transport coefficients, one of which is the usual shear
viscosity. We then apply the AdS/CFT duality for ${\cal N}=4$ SUSY in order to
compute the retarded correlators of the energy-momentum tensor. From these
correlators we determine a large set of transport coefficients of third- and
fourth-order hydrodynamics. We find that higher order terms have a tendency to
reduce the effect of viscosity.
