Overview
CK-4 10W-40 is a fully synthetic diesel engine oil in the SAE 10W-40 viscosity grade, formulated to API CK-4. API defines CK-4 for high-speed four-stroke diesel engines designed to meet 2017 model-year on-highway and Tier 4 non-road emission standards, and for earlier diesel engines.
The specification table publishes typical values from the product data sheet, each with its ASTM method: kinematic viscosity at 40 °C and 100 °C, cold-cranking viscosity, base number, Noack volatility and foaming tendency, plus viscosity after shear and copper corrosion. Check those values and the API category against the engine manufacturer's requirement before ordering.
Application
High-speed four-stroke diesel engines
Engines whose manufacturer specifies API CK-4, or an earlier API diesel category that CK-4 is intended to cover.
Application
On-highway and non-road equipment
API scopes CK-4 to engines built for on-highway and Tier 4 non-road emission standards, which covers trucks, buses and off-road machinery whose manuals call for it.
Application
Operating climate suited to SAE 10W-40
Cold-start performance is rated at -25 °C under SAE J300; choose this grade where ambient temperatures and the manufacturer's viscosity chart allow 10W-40.
Feature
Inside the SAE J300 limits for 10W-40
Kinematic viscosity at 100 °C is 15.1 cSt, within the SAE J300 band for grade 40 (12.5 to below 16.3 cSt). Cold-cranking viscosity is 5,650 cP at -25 °C, under the 7,000 cP maximum that SAE J300 sets for 10W.
Feature
Base number 12.3 mg KOH/g
The total base number (TBN, ASTM D2896) of 12.3 mg KOH/g is the oil's alkaline reserve for neutralising acidic combustion by-products between drains.
Feature
Viscosity index 173, Noack 6.2 %wt
A viscosity index of 173 (ASTM D2270), Noack evaporation loss of 6.2 %wt (ASTM D5800) and a pour point of -36 °C (ASTM D97) are published as typical values.
