12 November 2002

The California Air Resources Board (ARB) has verified the Donaldson Company diesel oxidation catalyst (DOC) mufflers for use in California diesel retrofit programs. In some configurations, the DOCs is combined with the Donaldson Spiracle™ closed crankcase filtration system, which controls particulate matter (PM) emission from the crankcase. All systems, including the DOC + Spiracle and DOC only configurations, are verified as Level 1 device, i.e., they reduce PM emissions by at least 25% (and not more than 50%). The DOC + Spiracle™ system verification applies to most post-1991 engines used in on-road applications. It is the first ARB verification for an emission control system applicable to pre-1994 engines.

Donaldson systems utilize two types of DOCs: the more active 6100 Series DOC suitable for ultra low sulfur fuel applications, and the sulfate-suppressed 6000 Series DOC, suitable for use with all on-road commercial fuels in California. The ARB verified the following three system configurations:

  1. The Donaldson DCM diesel oxidation catalyst mufflers with 6000 Series catalyst formulation plus Spiracle™ closed crankcase filtration systems with commercially available California diesel fuel or fuel with a lower sulfur content. This system can be used in most on-road engines in model years 1991-2002.
  2. The Donaldson DCM DOC mufflers with 6100 Series catalyst formulation plus Spiracle™ closed crankcase filtration systems with ultra low sulfur fuel (15 ppm S or less). This system can be used in most 1991-2002 on-road engines.
  3. The Donaldson DCM DOC mufflers with 6100 Series catalyst formulation alone on 15 ppm or less sulfur fuel. This system can be used in engines used in most on-road applications in model years 1994-2002.

All of these engines are four-stroke, turbocharged, with horsepower rating of greater than 150 bhp and were certified in California to the 0.1 or 0.25 g/bhp-hr PM emission standard when new. The complete list of engine models is available from the ARB Verified Devices web page.

In the the verification letter, the ARB estimates that the Donaldson systems “will incur no discernible fuel economy penalty when used in a compatible application”.

According to press reports (Minneapolis Star Tribune), Donaldson forecasts potential revenue in relation to the California approval of up to $15 million during the next 18 months and up to $100 million in California during the next five years. The DOC + Spiracle™ combination system will be sold on a retrofit basis for about $2,000 per vehicle.

The list of ARB-verified emission control devices from other manufacturers includes the following products:

  • CRT diesel particulate filters by Johnson Matthey, verified as Level 3 (85% PM emission reduction) device for most 1994-2002 model year diesel engines in on-road applications
  • Catalyzed DPX diesel particulate filters by Engelhard, verified as Level 3 device for most 1994-2002 model year diesel engines in on-road applications
  • Diesel particulate filter by Engelhard, verified as Level 3 device for Caterillar engines which have been converted to duel fuel (natural gas - diesel) operation by Power Systems Associates
  • Cleaire “Flash and Catch” systems, various configurations verified for Cummins M11 engines in long-haul truck application

ARB verification letter

Source: California ARB