This report responds to a request from Senator Jeff Sessions for an analysis of the environmental and energy efficiency attributes of light-duty diesel vehicles. 
Specifically, the inquiry asked for a comparison of the characteristics of diesel-fueled vehicles with those of similar gasoline-fueled, E85-fueled, and hybrid vehicles,
as well as a discussion of any technical, economic, regulatory, or other obstacles to increasing the use of diesel-fueled vehicles in the United States

Contents	(complete Report)
Executive Summary
Preface and Contacts
Chapter 1. Introduction
Chapter 2. Comparison of Light-Duty Vehicle Greenhouse Gas Emissions
Chapter 3. Efficiency Benefits, Past Experience, and Current Market Issues
Chapter 4. Fuel Quality and Availability
Appendixes
Appendix A. Analysis Request Letter
Appendix B. GREET Greenhouse Gas Emissions and Fuel Economy Projections for Various Vehicle Types, 2010
Appendix C. GREET Electricity Generation Mix for Transportation Use
Appendix D. Shares of New Light-Duty Diesel Vehicles Sold in U.S. and Western European Markets
Appendix E. Yearly Gasoline and Noncommercial Diesel Fuel Prices and Tax Rates