The Manufacturers of Emission Controls Association recently released the results of its survey showing its member companies sold nearly 25,000 diesel retrofit devices in 2010.

According to the results, the total number of verified (U.S. EPA- and/or California ARB-verified) diesel retrofit devices (for both on-road and off-road diesel engines) sold in the U.S. by MECA member companies in 2010 was 24,640.

The sales break down this way:

* 41% were diesel particulate filters (includes both passively regenerated and actively regenerated filters)

* 40% were diesel oxidation catalysts

* 8 percent were flow-through filters. This total also includes 2,580 closed-crankcase filters.

In California, 7,487 diesel retrofit devices were sold, of which 77% were DPFs and 23% were flow-through filters.

Compared to the results of MECA's previous surveys, the number of diesel particulate filters and diesel oxidation catalysts sold in 2010 remained about the same (20,099 diesel particulate filters and diesel oxidation catalysts were sold in the U.S. by MECA member companies in 2010, 20,197 in 2009, 22,300 in 2008, and 20,553 in 2007).

MECA says sales of diesel particulate filters and diesel oxidation catalysts have remained steady over the past several years. Funding from the Diesel Emissions Reduction Act (DERA) through EPA's National Clean Diesel Campaign has helped provide funding and financial incentives for many clean diesel projects (using retrofit devices, as well as engine repowers and vehicle replacements).

However, MECA says, more dedicated and innovative funding is needed to clean up all of the diesel engines in the existing fleet. DERA was re-authorized at the end of last year for FY 2012-2016, but no funding has been appropriated yet.

In California, ARB's in-use on-road diesel vehicle regulation and in-use off-road diesel vehicle regulation are expected to generate additional demand for diesel retrofit devices (primarily diesel particulate filters), but amendments to the regulations approved in December 2010 meant to give fleets more time to comply due to the economic recession will slow the pace of retrofit sales and depress the total retrofit market opportunity in the state.