Alternative fuels for vehicles fleet demonstration program final report. Volume 1: Summary

The Alternative Fuels for Vehicles Fleet Demonstration Program (AFV-FDP) was a multiyear effort to collect technical data for use in determining the costs and benefits of alternative-fuel vehicles in typical applications in New York State. During 3 years of collecting data, 7.3 million miles of driving were accumulated, 1,003 chassis-dynamometer emissions tests were performed, 862,000 gallons of conventional fuel were saved, and unique information was developed about garage safety recommendations, vehicle performance, and other topics. Findings are organized by vehicle and fuel type. For light-duty compressed natural gas (CNG) vehicles, technology has evolved rapidly and closed-loop, electronically-controlled fuel systems provide performance and emissions advantages over open-loop, mechanical systems. The best CNG technology produces consistently low tailpipe emissions versus gasoline, and can eliminate evaporative emissions. Reduced driving range remains the largest physical drawback. Fuel cost is low ($/Btu) but capital costs are high, indicating that economics are best with vehicles that are used intensively. Propane produces impacts similar to CNG and is less expensive to implement, but fuel cost is higher than gasoline and safety codes limit use in urban areas. Light-duty methanol/ethanol vehicles provide performance and emissions benefits over gasoline with little impact on capital costs, but fuel costs are high. Heavy-duty CNG engines are evolving rapidly and provide large reductions in emissions versus diesel. Capital costs are high for CNG buses and fuel efficiency is reduced, but the fuel is less expensive and overall operating costs are about equal to those of diesel buses. Methanol buses provide performance and emissions benefits versus diesel, but fuel costs are high. Other emerging technologies were also evaluated, including electric vehicles, hybrid-electric vehicles, and fuel cells