We present a study of the effect of upwinding on stabilisation of both advective and pressure terms in a family of primitive-variable Navier-Stokes solvers. We consider two MUSCL schemes, the first one applies to compressible flow, the second one to incompressible flow. We illustrate the fact that both numerical models suffer oscillations if a minimal (but not large) amount of upwinding is not associated with acoustics, while advection can be stabilized by the physical diffusion terms when the mesh Reynolds number is small enough.