Gearbox

• An automobile's gearbox is an intricate arrangement of grooved wheels and cylinders. The assembly is responsible for transmission of energy from rotational motion and controlling parameters such as torque, direction and speed, for optimal performance in different conditions.
  
  

Gear Oil Features

• Gear oils are designed so that the fluids are able to offer reliability and efficiency across a range of different speeds, temperatures and oil contamination levels. Gear oils should be durable, be efficient in reducing friction and be low-maintenance.
  
  

Additives

• Different additives give special properties to gear oils. Rust and oxidation inhibitors are added to rust and oxidation (R and O) preventive gear oils on a mineral base; demulsifiers and fatty oils are added to compounded gear oils for better lubricity. Other oil types, such as extreme pressure (EP) and synthetic, also contain additives.
  
  

Viscosity

• Viscosity of gear oils is a physical attribute of the fluid that effects different parameters; low viscosity oils are thinner, support high speeds and low friction, have smoother tooth grooves and give efficient cooling. High viscosity oils, on the other hand, are thicker and are more favorable for lower speeds.
  
  

Grading

• According to the Society of Automotive Engineers (SAE), all engine oils and gear oils should be graded. There are two classes of gear oils, based on viscosity, known as monograde and multigrade.