A method and system to blend components to form a lubricant having a predetermined characteristic. The method includes determining the characteristic from a model that relates that characteristic as a function of the amount of its components and properties of the components. These predetermined characteristics include KV (kinematic viscosities), CCS (cold cranking simulator), HTHS (high temperature, high shear viscosity), Noack Volatility, MRV (mini-rotary viscometer), Brookfield Viscosity, Soot-Dispersancy, Oxidation, Deposit, Wear, Sulfur, Phosphorus, Base Number, Color, Ash Content, Aniline Point, Acid Number, Viscosity Index, Turbidity, Demulsibility, Foam Stability, Acute Toxicity, Biodegradability, Nitrogen, and Detergency.