PUMP GP-PISTON 1712092 - Caterpillar

The proper SAE grade of oil to select is determined by the minimum outside temperature at which the engine will be started and the maximum outside temperature in which the engine will be operating. This recommendation is to ensure the correct viscosity is used until the next oil change. The required performance criteria for the oil is defined in the previous Lubricant Specification section.The minimum temperature for the viscosity grade provides guidelines for the lowest starting temperature with a "cold soaked" engine. Base stocks for blending the oil formulations do differ and variations can exist within a viscosity grade on low temperature characteristics. Therefore, a particular oil may allow lower starting temperatures than given in the following chart. Your oil supplier can provide additional information on oil properties.The recommendation would be to use the highest viscosity oil possible. Even though the ambient temperature may be low, operating engines can still be subjected to normal oil temperatures because of regulated temperature components. The higher viscosity oils will provide better protection to all components which it contacts during the full operating cycle.To determine if the oil in the crankcase will flow in cold weather, remove the oil dipstick before starting. If the oil will flow off, the oil is fluid enough to circulate properly.