Density, parallel velocity, transverse velocity, and pressure in the laboratory frame for two different simulations. In both cases, the coarse grid is set by n_x = 64 with 11 levels of refinement based on pressure gradients. The solid line shows a simulation where additional refinements occur based on Lorentz factor gradients. The result is superimposed to the analytic solution (Giacomazzo & Rezzolla 2006) given in blue. The red dashed line in the upper panel shows the refinement levels, based on the Lorentz factor gradients.