U.S. Environmental Protection Agency

February, 2002

Document Released for Public Information

"Update Heavy-Duty Engine Emission Conversion Factors for MOBILE6:
Analysis of BSFCs and Calculation of Heavy-Duty Engine Emission
Conversion Factors"

Report Number   EPA420-R-02-005     (M6.HDE.004)
 
	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 BSFCs and Calculation of Heavy-Duty Engine Emission
Conversion Factors" for public information.  This document EPA420-R-02-005, also known as 
M6.HDE.004, is available at the MOBILE6 section of the OTAQ Web Site 
(http://www.epa.gov/otaq/m6.htm). 

	
	This report discusses the calculation of average engine
brake-specific fuel consumption(BSFC) for model years 1987 through
1996, and calculates conversion factors for all heavy-duty vehicle
weight classes.  In addition, it projects conversion factors for model
years 1997 through 2050.

	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 BSFCs and Calculation of Heavy-Duty Engine Emission
Conversion Factors".  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.