Mobil Delvac™ Extreme FE 10W-30 is a synthetic, high-performance diesel engine oil that helps extend engine life while providing long drain capability for modern diesel engines operating in extreme conditions. It meets or exceeds the new API FA-4 specification for fuel-efficient engine oils, as well as key original equipment manufacturer (OEM) requirements. Mobil Delvac Extreme FE is formulated with a blend of synthetic basestocks and a boosted additive system tailored to deliver extended performance for up to two times beyond OEM recommended oil drain intervals. The proprietary formulation delivers excellent wear protection, unsurpassed oxidation stability, and outstanding TBN retention.