June 26, 1998

Document Released for Stakeholder Review and Comment

Hot Soak Emissions as a Function of Soak Time

Report Number EPA420-P-98-018

The Office of Mobile Sources, Assessment and Modeling Division,
announces the release of "Hot Soak Emissions as a Function of
Soak Time" for stakeholder review and comment. This document
EPA420-P-98-018 also known as document M6EVP007.PDF /
M6EVP007.WPD is available at the MOBILE6 section of the OMS Web
Site (http://www.epa.gov/omswww/models.htm).

This document presents an analysis of the rate hot soak emissions
decline over the one hour time period. A quadratic equation was
used to fit the hot soak emission results versus soak time. The
results indicate that the majority of the hot soak emissions
occur near the beginning of the hot soak test. This information
will be used in MOBILE6 with the hot soak emissions and activity
information from the two documents "Soak Length Activity Factors
for Hot Soak Emissions" (M6.FLT.004), and "Hot Soak Emissions"
(M6.EVP.004).

Comments on this report and its proposed use in MOBILE6 should be
sent to the attention of Ed Glover. Comments may be submitted
electronically to mobile@epa.gov, or by fax to (734) 214-4939, or
by mail to MOBILE6 Review Comments, US EPA Assessment and
Modeling Division, 2000 Traverwood Drive, Ann Arbor MI 48105.
Electronic submission of comments is preferred. In your comments,
please note clearly the document that you are commenting on
including the report title and the code number listed. Please be
sure to include your name, address, affiliation, and any other
pertinent information.

This document is being released and posted on June 26, 1998.
Comments will be accepted for sixty (60) days, ending August 26,
1998. EPA will then review and consider all comments received,
and will provide a summary of those comments and how we are
responding to them in the form of a followup document within 30
days after the close of the comment period (by September 26,
1998).

Thank you for your continuing interest in the development of
MOBILE6.

Sincerely,

Emission Inventory Group, 
Assessment and Modeling Division 
US EPA
Office of Mobile Sources