Tankmix additive concentrates containing a surfactant and a petroleum derived paraffinic oil and the use of aqueous pesticide spray mixtures incorporating such tankmix additive concentrates are described. The tankmix additive concentrates described herein include from 0.5 to 50 weight percent of a polymeric surfactant, a anionic ester surfactant, a nonionic surfactant, or mixtures thereof, and from 1 to 95 weight percent of a petroleum derived paraffinic oil. The tankmix additive concentrates form a stable emulsion upon dilution into a pesticide spray mixture.