Engine Oils
Background & Properties
castrol.com/GPS
800 255 4417
May 2025
GPS
Industry Specifications
Test length: 50 hours
Approximate power output: 30-34 kW
API CK-4 Pass/Fail Criteria:
Average Pin Wear, microns max: 7.6
API CK-4 Bench Tests
A bench test differs from an engine test in that it is performed in a laboratory, not on a full engine. Bench tests
are less expensive to run and help round out the performance measurement for the API CK-4 category.
Noack or Volatility Bench Test ASTM D5800
Scope:
e Noack test measures oil volatility at high temperatures. As temperatures rise, any fluid, even engine oil,
has a tendency to evaporate. is test ensures that API CK-4 oils will experience only minimal evaporation
due to temperature.
During the Noack Volatility Test, a sample of oil is placed in the test machine and held at elevated
temperatures with a slight vacuum for one hour. e oil sample's weight is noted at the beginning and end of
the bench test. e Noack Volatility Test measures oil volume to assure that the oil experiences only minimal
evaporation at high temperatures.
Test Conditions:
e test oil is heated for one hour at 250° C. e sample is under vacuum with resulting oil vapors drawn off
by an air stream. e amount of vapor indicates volatility of oil and oil consumption.
API CK-4 Pass/Fail Criteria:
Loss @ 250°C, percent max volatility: 13.0%
Kinematic Viscosity/SAE J300 ASTM D445
Scope:
is simple test describes the viscosity of the oil at various temperatures.
Test Conditions:
e flow of the oil against gravity is measured using a calibrated glass tube immersed in a heated bath.
API CK-4 Pass/Fail Criteria:
@ 100° C: 9.3 to <12.5 cSt for XW-30
12.5 to <16.3 cSt for 15W-40
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