Improving product performance ExxonMobil develops products that reduce energy use and emissions throughout our customers’ activities and supply chains, including Mobil Delvac fully synthetic, heavy-duty diesel engine oil that combines advanced engine protection with enhanced fuel economy potential; Mobil 1™ Advanced Fuel Economy — a high-performance synthetic engine oil that can help improve fuel economy by up to 2 percent; and Mobil DTE 10 Excel™ — a series of hydraulic oils that increases equipment output, resulting in potential for reduced energy consumption and operating costs.