High output and low emission diesel engines significantly increase the demands on engine lubricants. Tighter engine designs reduce oil consumption, resulting in less new oil to replenish depleted additives. The top piston fire ring is located higher on the piston, bringing the oil film closer to the combustion chamber where higher temperatures increase the thermal stress on the lubricant. Increased fuel injector pressure and retarded timing improve fuel combustion efficiency, but also result in higher engine temperatures and increased soot loading. Mobil Delvac Modern 15W-40 Super Defense is formulated from high-performance base oils and a balanced additive system to deliver optimal engine performance in modern diesel and gasoline engines as well as older models. Key benefits include: