Mobil Pegasus 605 is a high performance natural gas engine oil primarily intended for the lubrication of modern medium and high-speed four-cycle engines operating on fuel that contains corrosive materials such as hydrogen sulphide or halogens (compounds containing chlorine, fluorine, etc.). These engines are generally of the lean-burn design where increased manifold pressures prevent sufficient lubricant from reaching the valve guide areas resulting in low oil consumption which can lead to valve guide wear and valve recession. This effect also increases the potential for wear and acid attack of upper cylinder components from the corrosive materials generated during combustion. The Mobil Pegasus 605 is a 0.5% ash gas engine oil with exceptional reserve alkalinity designed to offset the negative effects of acidic materials on engine components. The excellent corrosion protection properties helps prevent corrosive wear in cylinders, valve areas and bearings which can result in longer engine life and lower maintenance costs. Mobil Pegasus 605 provides excellent anti-wear and anti-scuff performance which helps assure minimal piston scuffing, scoring and low cylinder liner and piston ring wear. This oil can also be used for the lubrication of the reciprocating compressors in landfill and biomas gas applications.