The paper presents an enhanced analysis of the Lax-Wendroff difference scheme-up to the eighth-order with respect to time and space derivatives-of the modified-partial differential equation (MDE) of the constant-wind-speed advection equation. The modified equation has been so far derived mainly as a fourth-order equation. The Π-form of the first differential approximation (differential approximation or equivalent equation) derived by expressing the time derivatives in terms of the space derivatives is used for presenting the MDE. The obtained coefficients at higher order derivatives are analyzed for indications of the character of the dissipative and dispersive errors. The authors included a part of the stencil applied for determining the modified differential equation up to the eighth-order of the analyzed modified differential equation for the second-order Lax-Wendroff scheme. Neither the derived coefficients at the space derivatives of order p ∈ (7 -8) in the modified differential equation for the Lax-Wendroff difference scheme nor the results of analyses on the basis of these coefficients of the group velocity, phase shift errors, or dispersive and dissipative features of the scheme have been published. The MDEs for 2 two-step variants of the Lax-Wendroff type difference schemes and the MacCormack This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.