California Air Resources Board

Presentation for July 8th, 2020 DF workshop covers the following: 

• Manufacturers of heavy-duty on- and off-road diesel engines establish deterioration factors (DF) to estimate emissions at the end of useful life
• Testing has shown that emissions rates on engines with SCR are increasing faster than DF’s indicate
• CARB/EPA are asking manufacturers to validate existing DFs to continue using them for future model years
• Examples of acceptable methods to validate DFs are provided