An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

Verified Technologies for SmartWay and Clean Diesel

Johnson Matthey Technology—Advanced Catalyzed Continuously Regenerating Technology (AdvCCRT) System

This retrofit technology is included on EPA's Verified Technologies List for Clean Diesel.

On this page:

Technology specifications

Engine Model/Application

On-highway, 4-cycle, light-, medium-, and heavy- heavy duty diesel engines; turbo-charged or naturally aspirated, EGR and non-EGR, and originally manufactured from 2002 through 2006 model years

Retrofit Fuel, Max Sulfur 15 parts per million (ppm)
Reduction in particulate matter (PM) 90%
Reduction in nitrogen oxide (NOx) n/a
Reduction in hydrocarbons (HC) n/a
Reduction in carbon monoxide (CO) 50%

Top of Page

Criteria to achieve emission reductions

The following operating criteria must be met in order for appropriately retrofitted engines to achieve the emissions reductions above:

  1. The engine may or may not have a pre-existing original equipment manufacturer oxidation catalyst.
  2. The engine must not have a pre-existing diesel particulate filter.
  3. The engine must be certified at a PM emission level of at most 0.1 grams per brake horsepower-hour (g/bhp-hr).
  4. The engine must be electronically controlled.
  5. The engine should be well maintained and not consume lubricating oil at a rate greater than that specified by the engine manufacturer.
  6. Lube oil, or other oil, should not be mixed with the fuel.
  7. The engine must be operated on diesel fuel with a sulfur content of no more than 15 parts per million by weight.
  8. For reliable regeneration, the NOx to PM ratio, based on certified emissions levels, should be 20 or higher, and the engine cycle must be at 240° Celsius for 40% of the operation time. 

Top of Page

Verification Letter from EPA

You may need a PDF reader to view some of the files on this page. See EPA’s About PDF page to learn more.