  The application of Runge-Kutta schemes designed to enjoy a large region of
absolute stability can significantly increase the efficiency of numerical
methods for PDEs based on a method of lines approach. In this work we
investigate the improvement in the efficiency of the time integration of
relaxation schemes for degenerate diffusion problems, using SSP Runge-Kutta
schemes and computing the maximal CFL coefficients. This technique can be
extended to other PDEs, linear and nonlinear, provided the space operator has
eigenvalues with a non-zero real part.
