While Venus and Earth are similar in size, Venus does not appear to have developed the same system of mobile surface plates which dominates convective heat transfer from the interior of Earth. Numerical models with temperature dependence viscosity do not produce plate boundaries and are more closely reminiscent of Venus than Earth. We demonstrate that many puzzzling aspects of surface features on Venus are also found in the analysis of the surface observables in these models. Despite having no strong lithosphere, our calculations exhibit very high geoid/topography ratios and uncompensated short-wavelength topography. Surface heat flux values are not required to be very different from Earth-scaled values, and the mantle remains below the likely solidus. ¿ American Geophysical Union 1995.