The introduction of nanostructures in a liquid provides a means for changing the physical and/or chemical properties of the liquid. Improvements in heat transfer, electrical properties, viscosity, and lubricity can be realized upon dispersion of nanotubes in liquids. Stable dispersions of nanostructures are described and surfactants/dispersants are identified which can disperse nanostructures in petroleum liquid medium. The appropriate dispersant is chosen for the selected nanostructure material and the oil based medium and the dispersant is dissolved into the liquid medium to form a solution. The nanostructure is added to the dispersant containing the solution with agitation, ultrasonication, and/or combinations thereof. Nanostructures dispersed in a fluid form a nanofluid utilized as a shock absorber oil whereby the nanostructures serve to improve the viscosity index of the fluid or more particularly the shock absorber oil in the form of a lubricant additive.