There are differing yet strongly held views among the various "stakeholders" in the advanced fuel/propulsion system debate. In order for the introduction of advanced technology vehicles and their associated fuels to be successful, it seems clear that four important stakeholders must view their introduction as a "win": • Society, • Automobile manufacturers and their key suppliers, • Fuel providers and their key suppliers, and • Auto and energy company customers. If all four of these

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... from their own perspectives, are not positive regarding the need for and value of these advanced fuels/vehicles, the vehicle introductions will fail. This study was conducted to help inform public and private decision makers regarding the impact of the introduction of such advanced fuel/propulsion system pathways from a societal point of view. The study estimates two key performance criteria of advanced fuel/propulsion systems on a total system basis, that is, "well" (production source of energy) to "wheel" (vehicle). These criteria are energy use and greenhouse gas emissions per unit of distance traveled. The study focuses on the U.S. light-duty vehicle market in 2005 and beyond, when it is expected that advanced fuels and propulsion systems could begin to be incorporated in a significant percentage of new vehicles. Given the current consumer demand for light trucks, the benchmark vehicle considered in this study is the Chevrolet Silverado full-size pickup. How This Study Differs from Other Well-to-Wheel Analyses This study differs from prior well-to-wheel analyses in a number of important ways: 1. The study considers fuels and vehicles that might, albeit with technology breakthroughs, be commercialized in large volumes and at reasonable prices. In general, fuels and propulsion systems that appear to be commercially viable only in niche markets are not considered. 2. The study provides best estimates and associated confidence bounds of the criteria mentioned above to allow the reader to assess differences between fuel/vehicle propulsion systems on a more statistically sound basis. This approach provides not only the best estimate, but also a measure of the uncertainty around the best estimate. iii 3. The study incorporates the results of a proprietary vehicle model created and used by General Motors. 4. The well-to-wheel analysis involved participation by the three largest privately owned fuel providers: BP, ExxonMobil, and Shell. 5. The 15 vehicles considered in the study include conventional and hybrid electric vehicles with both spark-ignition and compression-ignition engines, as well as hybridized and non-hybridized fuel cell vehicles with and without onboard fuel processors. All 15 vehicles were configured to meet the same performance requirements. 6. The 13 fuels considered in detail (selected from 75 different fuel pathways) include lowsulfur gasoline, low-sulfur diesel, crude oil-based naphtha, Fischer-Tropsch naphtha, liquid/compressed gaseous hydrogen based on five different pathways, compressed natural gas, methanol, and neat and blended (E85) ethanol. These 13 fuels, taken together with the 15 vehicles mentioned above, yielded the 27 fuel pathways analyzed in this study. Format The study was conducted and is presented in three parts: • Well-to-Tank (WTT): consideration of the fuel from resource recovery to delivery to the vehicle tank, • Tank-to-Wheel (TTW): consideration of the vehicle from the tank to the wheel, and • Well-to-Wheel (WTW): integration of the WTT and TTW components. The following figure illustrates the stages involved in a full fuel-cycle analysis. Argonne's study covers the WTT (or feedstock and fuel-related) stages (Part 1). GM evaluated the fuel economy and emissions of various vehicle technologies using different fuels (TTW analysis) (Part 2). In a separate effort, Argonne's WTT results were combined with GM's TTW results to produce WTW results (Part 3).