CITGO CITGARD SynDurance Synthetic Heavy Duty Engine Oils utilize premium synthetic base stocks to improve high and low temperature properties that give maximum engine protection over a wider temperature range compared to conventional 15W-40 engine oil. The careful balance of synthetic components and wide range viscosities gives improved fuel economy and optimized engine oil change intervals when combined with LubeAlert HD® Oil Analysis Program. Since the introduction of lower emission engines, controlling soot has been one of the leading challenges for diesel engine oil. The advanced additive Soot Arrest™ Technology improves soot control and stabilizes viscosity in most severe operating conditions. CITGO CITGARD SynDurance Synthetic Heavy Duty Engine Oils are formulated with an extremely shear stable viscosity modifier to insure heavily loaded engine parts have protective oil films which provide superior wear protection and engine durability. With the future focus on reducing greenhouse gases and the carbon footprint, CITGO CITGARD SynDurance Synthetic Heavy Duty Engine Oil 5W-30 has proven to improve fuel economy compared to other viscosity grades while maintaining optimum engine durability. CITGO CITGARD SynDurance Synthetic Heavy Duty Engine Oils improve overall engine efficiency and prolong the life of the diesel particulate filters (DPF’s), and Diesel Oxidation Catalyst (DOC’s) low emission systems.