What does it mean to “retrofit” diesel vehicles and engines?
The term “retrofit” is broadly defined to include any technology, device, fuel or system that, when applied to an existing diesel vehicle or engine, achieves emission reductions beyond that required by EPA regulations at the time of a vehicle or engine’s certification. Retrofit technologies may include EPA verified emission control technologies and fuels and CARB-verified emission control technologies. Note that diesel technologies are verified for specific types of vehicles or engines, defined in the “applicability” sections of the EPA and CARB verified technology lists. (These lists can be accessed from: http://www.epa.gov/otaq/retrofit/verif-list.
