It has been suggested by Verigin et al. [1993> that the response of the Martian magnetotail to changes in the solar wind rain pressure indicates the presence of an intrinsic dipole magnetic field. 3-D hybrid particle simulations of Mars were performed including the magnetotail regions. The simulations are in agreement with published Phobos 2 data from the 3 elliptical orbits and reproduce the magnetopause diameter dependence on the solar wind ram pressure reported by Verigin et al. [1993>. However, the simulations were performed with no intrinsic field present, indicating that the dependence of the magnetotail width on ram pressure, if not a discriminator for the presence of the intrinsic field. ¿ American Geophysical Union 1995