Duratec ES 15W-40 is specifically 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.
Higher combustion temperatures can lead to increased oxidation and nitrogen oxide formation. Duratec ES natural-gas engine oil suppresses and controls oxidation and nitration throughout extended drain intervals, preventing sludge, varnish, plugged filters, and deposits.
Acid formation can lead to corrosive wear. Duratec ES has outstanding combustion acid-neutralization capability throughout extended drain intervals, which helps to prevent corrosion and protects critical engine parts.
In July, Castrol will be upgrading Duratec ES to meet the new Cummins CES 20092 spec. The new spec will provide significantly improved oxidation and thermal stability compared to previous versions.