The velocities of helium, oxygen, and hydrogen ions have been recorded over a full range of solar wind conditions by the ion composition instrument (ICI) and Los Alamos National Laboratory plasma instrument (LANLPI), respectively, aboard the ISEE 3 spacecraft between August 1978 and December 1979. Interspecie velocity differences were observed frequently. For solar wind velocities between 300 and 400 km s-1 the velocity exceeded the hydrogen velocity by 5 km s-1 on the average. For solar wind velocities between 400 and 500 km s-1 the average difference was 14 km s-1; however, no evidence was found for a systematic nonzero average difference between helium and oxygen ions even at the higher velocities. Velocity differences were examined in a number of streams and across a number of interplanetary shocks. Helium-hydrogen velocity differences are generally bounded by the Alfv¿n speed. Velocity differences show abrupt changes across interplanetary discontinuities, persumably tangential. Differences between the speeds of differently charged minor ions appear also to result from the electrostatic potential differences across the interplanetary shocks. The potential difference, calculated from the energy jump condition for a perpendicular hydromagnetic shock, is of the correct magnitude to produce the observed effects.