Mobil Pegasus™ 605 Ultra 40 is the latest generation of gas engine oil primarily intended for the lubrication of modern medium and high-speed four-cycle engines operating on landfill gas that contains contaminants such as hydrogen sulphide, halides or siloxane. Its formulation has been carefully balanced to provide extended oil drain intervals, control the formation of carbon and varnish deposits, with very good anti-wear and anti-scuff performance.