The EMission FACtors (EMFAC) model is used to calculate emission rates from all motor vehicles, such as passenger cars to heavy-duty trucks, operating on highways, freeways and local roads in California. EMFAC2007 is the most recent version of this model. 

For more information, please contact Jeff Long at (626) 450-6140.

REVISION: Both the EMFAC and OFFROAD Models develop CO2 and CH4 emission estimates; however, they are not currently used as the basis for ARB's official GHG inventory which is based on fuel usage information The ARB's official GHG inventory can be found at the link below:

http://www.arb.ca.gov/cc/inventory/inventory.htm

However, ARB is working towards reconciling the emission estimates from the fuel usage approach and the models.

EMFAC2007 [3MB] Dated November 2006

EMFAC2007 v2.3 User's Guide [PDF Format 2.7MB]

EMFAC2002 Training Materials

• Presentation [Powerpoint] [PDF]
• Description of Examples [MSWord] [PDF]
• Examples [zipped 3.3MB]