U.S. Environmental Protection Agency

February, 2002

Document Released for Public Information

"Update Heavy-Duty Engine Emission Conversion Factors for MOBILE6:
Analysis of Fuel Economy, Non-Engine Fuel Economy Improvements and Fuel Densities" 

Report Number   EPA420-R-02-006     (M6.HDE.002)
 
	The Office of Transportation and Air Quality, Assessment and 
Standards Division announces the release of "Update Heavy-Duty Engine Emission Conversion 
Factors for MOBILE6: Analysis of Fuel Economy, Non-Engine Fuel Economy Improvements and 
Fuel Densities" for public information.  This document EPA420-R-02-006, also known as 
M6.HDE.002, is available at the MOBILE6 section of the OTAQ Web Site 
(http://www.epa.gov/otaq/m6.htm). 

	This report discusses the analysis of fuel economy for heavy-duty
engines of model years 1987 through 1996, and fuel density for
gasoline and diesel.  It also examines the use of non-engine
fuel economy improvement devices for forecasting conversion factors in
the future.
	

	This report was originally released (as a draft) in January, 1998 under the 
title, "Update Heavy-Duty Engine Emission Conversion Factors for MOBILE6:
Analysis of Fuel Economy, Non-Engine Fuel Economy Improvements and Fuel Densities".  
It was subsequently revised in February, 2002, and the February, 2002 is now the final version.  This final revision incorporates suggestions and 
comments received from stakeholders during the 60-day review period and from peer reviewers.