Gasoline-Ethanol Blend Aging Effects on Engine Performance and Exhaust Emissions 2003-01-3184

Four samples of three different types of gasoline found in Brazil were tested to verify their aging effects on engine performance and exhaust emissions: two samples of regular gasoline, one sample of regular gasoline plus additives, and one sample of premium gasoline. The regular gasoline is the most commonly used automotive fuel in Brazil; regular plus additives contains an improved detergent capacity; and premium is a gasoline of higher octane number. All these types of gasoline are, in fact, a blend of approximately 75% gasoline and 25% ethanol, with the ethanol having an anti-knocking function. The gasoline samples were tested in a total period of six months, using a production 1.3-liter, four-cylinder, sixteen-valve engine mounted on a bench test dynamometer. Performance parameters and exhaust emissions levels were obtained for engine speeds of 1000 to 6000 rev/min. The general test results point to an increase in HC and CO emissions and in fuel consumption with fuel aging.