Nonroad underestimates Diesel PM from T4 engines

[danielbizercox]

Nonroad diesel T4 engines are assumed to be certified using 15 ppm sulfur fuel. However, the widely available nonroad diesel fuel assumed in the national fuel supply since 2012 is at 6 ppm sulfur. This results in a substantial PM adjustment for sulfur as described in Section 8 of EPA-420-R-18-009, sometimes enough to zero out all PM emissions from these equipment.

Since nonroad diesel T4 engines are allowed to be certified using fuel with a sulfur range of 7-15 ppm, EPA will be updating the certification sulfur value for these engines to 7 ppm in MOVES3.0.2.

This will be implemented via a database update. Users interested in implementing this fix before MOVES3.0.2 is released can follow the steps below:

1. Make a copy of the MOVES default database (for MOVES3.0.1, this is movesdb20210209) and name it movesdb20210209_fixissue28.
2. Using the new database, run the following SQL command (e.g, using HeidiSQL or MySQL Workbench):

   UPDATE movesdb20210209_fixissue28.nrsulfuradjustment 
   SET PMBaseSulfur = 0.0007
   WHERE engTechID IN (174, 175, 176, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007);

3. Configure MOVES to use your new database by updating the defaultDatabaseName entry in MOVESConfiguration.txt and maketodo.txt.