Summary of Research on the Use of Intermediate Ethanol Blends in On-Road Vehicles

The paper summarizes research on the use of intermediate ethanol blends in the U. S. vehicle fleet. Intermediate ethanol blends, fuels with ethanol content above 10%, are just being introduced in the U. S. for use in conventional vehicles. Thirty published studies are covered including the extensive program conducted by the Coordinating Research Council. The individual studies are grouped by vehicle performance aspect: driveability, exhaust emissions, evaporative emissions, flexible-fuel vehicles, onboard diagnostics, and durability of engine, fuel, and emissions control systems. Within each performance aspect, data are examined for common trends and potential fuel impacts. In some cases, results from similar programs are combined and analyzed. A variety of ethanol impacts on vehicle performance and emissions are identified and described. Emphasis is placed on impact areas or potential failure modes that have been identified and tested. Differences in vehicle responses to increasing ethanol content are id...