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Verified Technologies for SmartWay and Clean Diesel

Johnson Matthey Technology—Continuously Regenerating Technology3 (CRT3) Particulate Filter

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

On this page:

Technology specifications

Engine Model/Application

Highway, medium and heavy heavy-duty, 4-cycle, non-EGR; model year 1994 - 2006, turbocharged or naturally aspirated engines

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) 93%
Reduction in carbon monoxide (CO) 72%

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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 exhaust temperature must be at least 240° C for approximately 40 to 50 percent of the duty cycle. As there may be variations from application to application, data-logging and a review of actual vehicle operating conditions is required to ensure CRT3 compatibility.
  2. The engine’s exhaust must produce a NOx/PM ratio of at least 8, with an optimum ratio approaching 20. JM will make an assessment of the suitability of candidate engines, based upon certification emission levels or emission test data.
  3. The engine should be well maintained and not consume lubricating oil at a rate greater than that specified by the engine manufacturer.
  4. Johnson Matthey installs a backpressure monitor and high pressure indicator light on all vehicles equipped with a CRT.
  5. The engine must be operated with a fuel that contains a sulfur content of no more than 15 parts per million (ppm).

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Verification Letter from EPA

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