The need to improve fuel economy without sacrificing performance with today's “downsized” engines has led to a dramatic increase in the usage of sophisticated fuel management systems. In the 1987 model year, approximately 75% of the automobiles produced in the United States were fuel injected.Fuel injectors contain several seals that are critical to their operation. Because of the need to seal over a broad temperature range in the presence of aggressive fuel compositions that can contain alcohols, and the need to resist the attack of oxidized fuel that can be formed, most of these seals are now based upon fluoroelastomers.In order for the fuel injector to function properly, the injector nozzle must remain clean. Gasolines containing detergents, specifically designed to clean injectors, are widespread. These detergents can be based upon or contain chemicals that could prove harmful to the sealing components.As a result of testing several fluoroelastomer types in different detergent-containing gasolines, with and without alcohol extension, it was found that these detergents do not pose any threat when used at the manufacturers' recommended level.The purpose of this paper is to review the results of subjecting commercially available fluoroelastomers, commonly used in fuel systems, to various detergent-containing reference fluids for different times and temperatures.