Effects of Alcohol Fuels on Engine Wear

Abstract

Abstract : Research into the effects of alcohol on engine lubrication and wear has investigated four alcohol-containing fuels; pure methanol, pure ethanol, methanol in unleaded gasoline, and ethanol, in unleaded gasoline. This research work has indicated that during low-temperature engine operations such as winter commuter service and warmup, use of pure methanol may result in increased engine wear. This increased wear appears to be primarily a low-temperature problem. With the engine warmed to normal operating temperatures, this increased wear has not been observed. To this point, the research with ethanol-containing fuels has not detected any wear increases. This may be due to the short duration engine tests being conducted, but nevertheless indicates that increased wear should be of less concern with this fuel. Wear mechanism studies have indicated that corrosive attack within the piston ring and cylinder area by alcohol combustion byproducts is partially responsible for the increased wear. Investigation of alcohol and lubricant compatibility and physical removal of the lubricant films by liquid alcohol have provided additional insights into these wear phenomena. (Author)