  In this work, we improve the accuracy and stability of the lattice Boltzmann
model for the Kuramoto-Sivashinsky equation proposed in \cite{2017_Otomo}. This
improvement is achieved by controlling the relaxation time, modifying the
equilibrium state, and employing more and higher lattice speeds, in a manner
suggested by our analysis of the Taylor-series expansion method. The model's
enhanced stability enables us to use larger time increments, thereby more than
compensating for the extra computation required by the high lattice speeds.
Furthermore, even though the time increments are larger than those of the
previous scheme, the same level of accuracy is maintained because of the
smaller truncation error of the new scheme. As a result, total performance with
the new scheme on the D1Q7 lattice is improved by 92 $\%$ compared to the
original scheme on the D1Q5 lattice.
