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There are multiple strategies and technologies that are available to accomplish our goal of affecting one million engines in the Midwest. Some of these are highlighted below.

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Technologies and Strategies

Fuel Efficiency Technologies

Technologies are available to provide overall energy savings as well as emission reductions through:

Operational Strategies

In addition, there are operational efficiency strategies which can be implemented at locations including:


The use of advanced diesel fuels such as ultra-low sulfur diesel (ULSD).


Regular engine maintenance plays a critical role in ensuring proper engine performance. Engine rebuilding can significantly lower emissions in some cases.


Replacing entire vehicles or equipment may be the best, most cost-effective option for some of the oldest engines. The replacement engine may not necessarily be a conventional, newer and cleaner diesel engine, but could be an electric or hybrid engine.

Retrofiting Technologies for Emission Reductions

The installation of exhaust after-treatment technologies such as particulate filters (PDF) (4pp, 101K About PDF), oxidation catalysts (PDF) (2pp, 99K About PDF), exhaust gas recirculation (EGR), selective catalytic reduction (SCR) devices and NOx catalysts can reduce emissions of particulate matter and nitrogen oxides (NOx). EPA has developed the National Clean Diesel Campaign to encourage fleet owners and operators to reduce emissions from diesel engines today. There are technologies and fuels that can be implemented to reduce diesel emissions. EPA maintains a Technology Verification program so that manufacturers can introduce verified technologies to the market as cost-effectively as possible, while providing customers with confidence that verified technologies will provide emission reductions as advertised. This verification process evaluates the emission reduction performance of retrofit technologies, including their durability, and identifies engine operating criteria and conditions that must exist for these technologies to achieve those reductions.

EPA's Technology Verification program has a Verified Products Web site which discusses all the diesel retrofit products that have been approved for use in engine retrofit programs. Information is provided by manufacturer, including background on retrofit kits and the potential compatibility issues. Site provides the percent reduction (of verified or tested levels) that EPA will recognize for emission reductions within state air quality plans.

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