Which of the following is a typical lubricant additive category?

• A. Anti-wear agents, rust inhibitors, viscosity modifiers
• B. Colorants only
• C. Solvents
• D. Abrasives

Answer: (A)

Lubricant additives are designed to boost protection and performance beyond what the base oil provides. Anti-wear agents form protective films on metal surfaces under load, reducing metal-to-metal contact. Rust inhibitors guard against corrosion when moisture is present, helping prevent deterioration of components. Viscosity modifiers adjust how the oil behaves with temperature, keeping film strength high at elevated temperatures while still allowing good flow at cold starts. Together, these categories cover the main protective and performance roles of typical additive packages in lubricants. Colorants are mainly for identification, solvents serve to dissolve or blend fluids rather than provide protection, and abrasives would actually cause wear rather than prevent it.