Skip to main content

Oregon State Flag An official website of the State of Oregon »

What Can I Do?

Oregon DEQ works with fleet owners and operators to offer ways they can take advantage of the benefits of diesel engines, while reducing their emissions impact. Strategies for reducing diesel exhaust fall under three primary approaches: burning less fuel, burning cleaner fuel and burning fuel cleaner.

The easiest ways to reduce diesel exhaust and save money are to burn less fuel. Simple steps can result in significant savings in fuel costs and reduced pollution.

  • Don't idle. Stopping unnecessary idling saves money in fuel and maintenance costs. One gallon of fuel burns for every hour of idling.
  • Perform regular maintenance to improve efficiency and engine life. It can also prevent equipment failure.
  • Track fleet inventory. Tracking vehicle model year, usage, fuel consumption, average mileage and other baseline information allows fleet managers to make decisions about operational improvements.
  • Use auxiliary power units, which provide the utility of an engine idling with far less pollution and fuel use.
  • Driver trainings, like driver incentive programs, are often overlooked as an important way to ensure fuel saving measures are being followed and to maximize vehicle efficiency.
  • Employ on-board diagnostic systems, which are modernizing and becoming better at tracking fuel use and driver behavior.
  • Apply fuel savings measures, such as low-rolling resistance tires, automatic tire inflation and other aerodynamic features, as part of EPA's Smartway program for shippers and carriers.​

​There are an increasing number of cleaner fuels available for diesel engines, starting with ultra-low sulfur diesel fuel. This fuel is required for highway trucks and non-road applications, such as construction equipment.

There are other fuels, including biodiesel, compressed natural gas, ethanol, propane and electricity, that provide environmental benefits on their own. However, exhaust from a diesel engine is most effectively reduced at the lowest cost when clean fuels are combined with exhaust controls.

These alternative fuels have operational advantages in specific circumstances and can be an excellent solution for a fleet to lower their emissions, and in some cases, offer operational savings. For fleets that remain committed to diesel, cleaner fuels like ultra-low sulfur diesel, renewable diesel and biodiesel can be combined with advanced exhaust controls to make the most environmentally cost effective solution.​

This approach refers to installing advanced exhaust controls (retrofitting vehicles and equipment), or replacing (repowering) engines.

Of the three approaches, retrofitting is the most cost-effective strategy on a cost per ton of pollutant-reduced basis. Typically, diesel retrofits involve adding a device to remove emissions from the engine exhaust. Retrofits can be very effective, eliminating up to 90% of pollutants, depending on the device. Some examples of devices are diesel oxidation catalysts, diesel particulate filters and closed crankcase ventilation systems.

DEQ offers technical assistance on these approaches and can refer fleet managers to vendors and other resources for more information. Grant money may be available to help with costs.​

If the retrofit project is for an on-road medium- or heavy-duty vehicle intended for a DEQ certification in accordance with the Oregon Department of Transportation registration and titling prohibitions (ORS 803.591), the retrofit technology must meet the criteria for DEQ-Approved Retrofit Technology. To participate in the program, the vehicle owner will need to agree to the program requirements and submit an application that includes approved retrofit installation and vehicle information.

Visit the Oregon Diesel Retrofit Compliance Program web page​ for more information.

Additional Resources

  • MECA - Manufacturers of Emission Controls Association; nonprofit association providing technical assistance on emission control technology
  • Diesel Technology Forum - nonprofit educational organization representing the diesel industry