U.S. Environmental Protection Agency
Office of Mobile Sources
April 1999


Evaporative MOBILE5b allows the user to estimate benefits
of proposed Tier 2 evaporative control on LDVs and LDTs.
Details of the model are contained in "A Modified Version of
MOBILE5b for Evaluation of Proposed Tier 2 Evaporative Emission
Standards", Memorandum from David Brzezinksi to Docket A-97-10.

The input and output files used for generating evaporative
VOC inventories for LDVs, LDTs and HDGVs are identical
for the baseline and control cases, with the exception of the 
"Evap Control Flag" as detailed in the above memo.  The input/output 
files contained here are a subset of all possible files; 
the files not included can be generated by changing the 
"Evap Control Flag" as appropriate.

Details of the regional scenarios (e.g. I/M program) are contained 
in "Development of Light-Duty Emission Inventory Estimates in the 
Notice of Proposed Rulemaking for Tier 2 and Sulfur Standards", 
EPA Report EPA420-R-99-005.  

Naming Key:

"NTH" = North, "STH" = South
"NE" = No evaporative I/M, "EV" = Evaporative I/M
## = RVP = #.# (e.g., 87 = RVP of 8.7 psi)

If the file name prefix ends with a "2", the Evap Control Flag 
is set to 2, meaning the proposed Tier 2 standards are in effect.
File prefixes without this are set in the baseline configuration
(Evap Control Flag = 1), which results in no change from MOBILE5b.

The generation of light-duty evaporative inventories is detailed in 
"Development of Light-Duty Emission Inventory Estimates in the 
Notice of Proposed Rulemaking for Tier 2 and Sulfur Standards", 
EPA Report EPA420-R-99-005.  The generation of heavy-duty gasoline
evaporative inventories (which are not affected by the proposed
Tier 2 controls) is detailed in "Development of Heavy-Duty Gasoline 
Emissions Inventories for the Tier 2/Sulfur NPRM", Memorandum from 
John Koupal to Docket A-97-10.