Mobil Delvac XHP Extra 10W-40 is a synthetic engine oil with extra high performance for heavier diesel engines, and is specially designed to provide outstanding lubrication of modern diesel engines in demanding driving conditions. The oil is based on synthetic base oils which provide excellent flowability at low temperatures, maintaining high viscosity at low temperatures, low volatility and improved fuel economy. The Mobil Delvac XHP Extra 10W-40 is designed to provide long shift intervals in modern diesel engines.