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Verified Technologies for SmartWay and Clean Diesel

Donaldson Technology—Series 6400 Diesel Oxidation Catalyst (DOC) & Spiracle Closed Crankcase Filtration System

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

On this page:

Technology specifications

Engine Model/Application

Highway, heavy-heavy and medium-heavy duty, 4 cycle, non-EGR, model year 1991 - 2003; turbocharged or naturally aspirated 

Retrofit Fuel, Max Sulfur 15 parts per million (ppm)
Reduction in particulate matter (PM)a 28%
Reduction in nitrogen oxide (NOx) n/a
Reduction in hydrocarbons (HC) 50%
Reduction in carbon monoxide (CO) 23%

a - Total PM reduction figures reflect reductions from both tailpipe and crankcase emissions.

Baseline assumes an unmodified engine running on fuel 15 ppm sulfur or less

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Criteria to achieve emission reductions

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

  1. The engine must be operated on ultra-low sulfur diesel fuel (ULSD) of 15 ppm or less.
  2. The engine exhaust temperature must be at least 150° C during its duty cycle.
  3. The engine must be well maintained and not consume lubricating oil at a rate greater than that specified by the engine manufacturer.
  4. The vehicle may not be equipped with an oil burning system and lube oil or other oils may not be mixed with the fuel.
  5. The engine must not have been originally certified or equipped with a diesel oxidation catalyst or diesel particulate filter.
  6. Spiracle™ must be installed and maintained as described in the April 1, 2011 EPA approval.

Verification Letter from EPA

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