API - Transmission Classification: API-GL-1

For axle transmissions with spiral gears and worm screw and certain manual transmissions. May contain additives: antirust, antioxidant, antifoam and an agent which lowers the point of solidification.

API-GL-2

For worm-screw transmissions in which a GL-1 oil is insufficient.

API-GL-3

For axle transmissions with spiral gears that function at moderate speeds and medium service for which a GL-1 oil is insufficient.

API-GL-4

For spiral-gear transmissions and special hypoid transmissions for vehicles which operate in high speed conditions at low torque or at low speed at high torque. Anti-wear and extreme pressure additives are often integrated.

API-GL-5

Same as previous case but under high-speed conditions generating extremely low torque and low speed at high torque. Anti-wear and high pressure additives are often used.