Extreme tribology refers to tribological situations under extreme operating conditions which can be related to high loads and/or temperatures, or severe environments. Also, they may be related to high transitory contact conditions, or to situations with near-impossible monitoring and maintenance opportunities. In general, extreme conditions can typically be categorized as involving abnormally high or excessive exposure to e.g. cold, heat, pressure, vacuum, voltage, corrosive chemicals, vibration, or dust. The extreme conditions should include any device or system requiring a lubricant operating under any of the following conditions: