Engine Oils
Product Data
castrol.com/GPS
800 255 4417
May 2025
GPS
Castrol
®
Duratec
™
ES 15W-40
Features/Benefits
Castrol Duratec ES 15W-40 enables "extreme" extended drain intervals while maintaining outstanding
protection and delivers an advanced detergent/dispersant system that has been designed to reduce deposit
formation and improve oxidation characteristics while offering excellent corrosion control, TBN retention and
outstanding wear control. User benefits include:
• Exceptional nitration and oxidation control compared to conventional on-road natural gas engine oil
• Specially designed for on-road trucks
• Exceptional anti-wear and extreme-pressure protection
• Reduces deposits and maintains engine cleanliness
• Wide range of operating temperatures
Castrol Duratec ES 15W-40 is designed for use in a wide range of natural gas equipment including Cummins,
Mack, Volvo, and other on road engines requiring a low-ash natural gas engine oil.
Industry Approvals and OEM Specifications by Grade
• Cummins CES 20092
Typical Properties
SAE Grade Method Units Typical
Kinematic Viscosity @100°C, cSt ASTM D445 mm
2
/s 15.1
Kinematic Viscosity @40°C, cSt ASTM D445 mm
2
/s 107
Viscosity Index ASTM D2270 -- 148
Sulfated Ash, %wt ASTM D874 % wt. 0.9
Total Base Number, Mg KOH/g ASTM D2896 mg/g KOH 6.7
Pour Point, °C ASTM D97 °C -42
Appearance Visual Clear and Bright
Due to continual product research and development, the information contained herein is based on products purchased in the U.S. and
subject to change without notification. Typical properties may vary slightly.
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