  The behaviour of extended particles with exclusion interaction on a
one-dimensional lattice is investigated. The basic model is called $\ell$-ASEP
as a generalization of the asymmetric exclusion process (ASEP) to particles of
arbitrary length $\ell$. Stationary and dynamical properties of the $\ell$-ASEP
with periodic boundary conditions are derived in the hydrodynamic limit from
microscopic properties of the underlying stochastic many-body system. In
particular, the hydrodynamic equation for the local density evolution and the
time-dependent diffusion constant of a tracer particle are calculated. As a
fundamental algebraic property of the symmetric exclusion process (SEP) the
SU(2)-symmetry is generalized to the case of extended particles.
