Impact of E100 Fuel on Bearing Materials Selection and Lubricating Oil Properties

As emission regulations tighten across various regions of the world there is a growing trend in the use of alternative fuels such as Ethanol being blended with gasoline. A notable case of Ethanol usage is found in South America with the widespread use of E100, which has no gasoline content and can often contain up to 10% water. Engine oil contamination by fuel is of major concern and under certain conditions can have negative effects on the durability of turbocharger components which come into contact with contaminated oil, particularly sliding bearings, but also compressor stage through crankcase ventilation system fed gas. The manner in which this effect takes hold can cause a decrease in the lubrication properties and increase in corrosiveness of the engine oil. This paper demonstrates the results of laboratory tests carried out where critical Turbocharger components were subjected to engine oils of various conditions in order to observe the effect of contaminated and aged oil that would potentially be fed to Turbochargers during operation on engines running E100 fuel. The measured effects can then be used as a basis for further component design improvements.