1 800 255 4417
www.castrol.com/GPS
Engine Oils
Product Data
Castrol
®
Duratec
™
ES 15W-40
September 2019
Full-synthetic technology for extended drain intervals of up to
1,200 hours* in modern natural-gas engines
Castrol Duratec ES 15W-40 is a synthetic lubricant formulated for use
in natural gas-fueled engines where minimal thermal degradation and
good deposit control is expected. Castrol Duratec ES 15W-40 provides
outstanding resistance to nitration and oxidation compared to mineral
on-road natural gas engine oil (NGEO) and meets the performance requirements of many of today's mobile natural
gas-fueled engines. Castrol Duratec ES 15W-40 provides improved cold temperature engine starting and reduced oil
consumption relative to single grade natural gas fueled engine oils.
Safely Extends Drain Intervals While Keeping Engines Clean
Castrol Duratec ES 15W-40 is speci cally formulated for modern natural gas engines with high-quality synthetic
base oils that take performance to the next level—enabling drain intervals up to 1,200 hours.* Although natural gas
engines burn cleaner, they also burn hotter, making acid neutralization and oxidation and nitration control critical in
protecting engines from deposits and wear over the useful life of the oil.
Duratec ES meets the latest Cummins CES 20092 speci cation and is backwards compatible.
Outstanding Acid Neutralization
Acid formation can lead to corrosive wear. Castrol Duratec ES has outstanding combustion acid-neutralization
capability throughout extended drain intervals, which helps prevent corrosion and protect critical engine parts.
Suppresses Oxidation and Nitration
Higher combustion temperatures can lead to increased oxidation and nitrogen oxide formation. Castrol Duratec ES
natural gas engine oil suppresses and controls oxidation and nitration throughout extended drain intervals, preventing
sludge, varnish, plugged lters, and deposits.
Excellent Wear Control
In natural gas engines, ash deposits (rather than soot, as in diesel engines) are a primary contributor to wear on key
metal surfaces like cams and cylinders. Castrol Duratec ES provides excellent ash wear protection across extended
drain intervals.
*Extending oil drain intervals should only be done in conjunction with a comprehensive used oil analysis
B 19
