Mobil Delvac 1 5W-40 is a fully synthetic, high-performance heavy-duty diesel engine oil designed to extend engine life and provide long drain capabilities. It is engineered for modern low-emission engines, including those with Exhaust Gas Recirculation (EGR), and is also suitable for older, well-maintained engines.

• Thermal and Oxidation Stability: Reduces low-temperature sludge buildup and high-temperature deposits.
• Fuel Economy: Formulated with low viscosity to potentially improve fuel efficiency compared to 15W-40 oils.
• Low-Temperature Performance: Ensures easier engine start-ups and immediate wear protection in cold conditions.
• Extended Service: Supports long drain intervals, helping to lower overall operating costs.
• Mixed Fleet Versatility: Meets API SL specifications, making it safe for high-performance gasoline engines in mixed fleets.