DEEP: Clean Diesel Technologies

Clean Diesel Technologies

Clean diesel technologies reduce emissions, improve performance and save fuel.  The first technologies to gain wide acceptance were emission controls installed in the exhaust systems of diesel-powered vehicles. These retrofit devices are effective in reducing the sooty particulate matter from diesel tailpipe emissions.  Idle reduction technologies, which allow drivers to turn off their engines and still have heat, air conditioning and electrical power, can reduce the whole range of diesel pollutants, including the greenhouse gases that are associated with climate change.  By decreasing wear and tear on the engine, reduced idling also lowers maintenance costs. The most recent additions to the clean diesel innovations are the fuel efficiency technologies that reduce friction.  These include low rolling resistance tires and aerodynamic trailers and cabs.
It should also be noted that new technologies are constantly being developed by engine manufacturers working to meet the increasingly stringent Federal emission standards for new vehicles implemented through EPA Regulatory Programs.   The benefits of the original equipment emission controls are so great that EPA and a number of states are creating incentives for the replacement of old diesel vehicles and engines with new. 


In 2015, DEEP became a SmartWay® Affiliate.  DEEP supports the goals of SmartWay and encourages you to explore the benefits of joining SmartWay. {SmartWay Affiliate Logo}

SmartWay is an innovative partnership of the U.S. Environmental Protection Agency that reduces greenhouse gases and other air pollutants and improves fuel efficiency using market-driven partnerships to help businesses move goods in the cleanest most efficient way possible. By providing a consistent set of tools and information needed to make informed transportation choices, SmartWay enables companies across the supply chain to exchange performance data in ways that protect the environment, enhance our nation’s energy security and foster economic vitality. To encourage continued improvement, SmartWay provides incentives and recognition for top performers. 

SmartWay aims to accelerate the availability, adoption and market penetration of advanced fuel efficient technologies and operational practices in the {Truck Aerodynamics} freight supply chain, while helping companies save fuel, lower costs and reduce adverse environmental impacts.

When the technologies for idle reduction, aerodynamic improvements, low rolling resistance tires and other retrofit technologies are installed, maximum benefits can be achieved. EPA has verified specific products and continues to evaluate and verify new products.

Find out more about SmartWay and learn how joining SmartWay can benefit your operations.

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Emission Control Technologies

{Diesel Filter} There are a variety of emission control technologies that can be installed on diesel engines to reduce pollution from diesel exhaust. While they are often referred to as “retrofit technologies, most diesel trucks manufactured since 2007 include such controls as original equipment.  These devices are also being phased in on diesel-powered construction equipment and marine engines.  The most commonly referenced retrofit technologies are diesel oxidation catalysts (DOCs), which function like catalytic converters in automobiles, and diesel particulate filters (DPFs).  EPA’s website has a good description of diesel retrofit technologies and their relative benefits.

The EPA and California Air Resources Board (CARB) have established certification processes to verify technologies for emission reduction capabilities.  The certification process provides a technical review and verification of manufacturer's emission reduction estimates.  EPA requires the use of technologies verified by either EPA or CARB for retrofit projects relying on Federal funding.  The EPA and CARB verification processes are described in the links provided below.

EPA's Verified Technology List

EPA’s Emerging Technologies List  - Note: The technologies on this list were included on the Emerging Technologies List for the program’s two-year limit and are no longer considered emerging technologies as designated by EPA. They are now classified as Verified (or Conditionally Verified), Certified, Pursuing Verification, or Not Pursuing Verification.

California Air Resources Board Verified Technology Pages

California Air Resources Board Level 1 Verified Technology Pages


Idle Reduction Technologies

{Truck APU}

Auxiliary Power Units (APUs): APUs are small diesel engines that provide cab heating, cooling and electricity without the idling of the main truck engine.  APUs reduce air pollution at rest areas, truck stops, pick-up and delivery locations, ports and in other places where trucks idle for extended periods either for rest or in queues. APU systems are also available to reduce idling from diesel locomotives.

{Truck Stop Electrification}

Truck-stop Electrification (TSE): Truck drivers typically idle their diesel engines to provide air-conditioning or heat to keep the engine and fuel warm in cold weather.  Stationary idle-reduction projects involve switching idling heavy duty diesel trucks to electricity to reduce greenhouse gas emissions and local air pollution.



Additional Technology References:

EPA's Technology Overview

EPA's Region 1 Technology Summary

EPA Diesel Retrofit Technology: An Analysis of the Cost-Effectiveness of Reducing Particulate Matter Emissions from Heavy-Duty Diesel Engines Through Retrofits 

US Department of Energy Vehicle Technologies Program

EPA Transportation and Air Quality

Content Last Updated on January 28, 2015