EP90 GL-4 is an automotive gear oil formulated with special friction modifiers , antiwear, anti-oxidant, anti-foam, anti-corrosion and extreme pressure additives.This combination ensures smooth squak and chatter free and good protection to the gear teeth. EP90 GL-4 is an automotive gear oil formulated with special friction modifiers virgin base oils, antiwear, anti-oxidant, anti-foam, anti-corrosion and extreme pressure additives.This combination ensures smooth squak and chatter free and good protection to the gear teeth.