Mobil DTE Oil Heavy is a high performance circulating oil (ISO VG 100) that has been produced for applications in, for example, steam and water turbine plants and other systems where the lubricating oil must have a long service life. Mobil DTE Oil Heavy has been produced from highly refined base oils and an additive system that provides an extremely high level of chemical and thermal stability, rapid and complete water separation and a high resistance to emulsion formation. They provide excellent protection against rust and corrosion, including resistance to salt water and they have good anti-wear properties. They have high viscosity indices that ensure minimal variation of the film thickness during temperature variations and minimal power loss during the heating period.