AG Mechanics CDE Practice Exam 2025 - Free AG Mechanics Practice Questions and Study Guide

Oil viscosity is a measure of the resistance to flow. Viscosity is a crucial property of oil as it determines how well the oil will flow and lubricate different components in machinery and engines. A higher viscosity means the oil is thicker and flows more slowly, while a lower viscosity indicates the oil is thinner and flows more freely. The ability to start in cold temperatures (Choice A), the rate of oxidation (Choice B), and the temperature rating (Choice D) are all important aspects of oil performance, but they do not directly relate to viscosity.