Ultra-Low Sulfur Diesel (ULSD)

Starting June 1, 2006, most diesel fuel in the U.S. will be "ultra-low sulfur diesel." The diesel fuel we use now is low sulfur diesel. Ultra-low sulfur diesel (ULSD) has less sulfur than low sulfur diesel, which makes it a cleaner burning fuel. Combined with cleaner burning diesel engines and motor vehicles, ULSD will help improve air quality.

Why is diesel fuel changing?

The Environmental Protection Agency (EPA) set new air quality standards to address health effects from diesel pollution. The petroleum industry is producing ULSD in order to meet these new standards.

What are the health effects of diesel pollution?

Diesel engines emit large amounts of hydrocarbons (the vapors you smell from gasoline or other petroleum products), nitrogen oxides (brownish gas that comes mainly from high heat combustion – as by a car engine), and particulate matter (like soot). These air pollutants contribute to serious public health problems, especially for children and elderly people. These health problems can result in:

How is ULSD better for health and the environment?

Because it contains less sulfur, ULSD enables diesel vehicles to use cleaner technologies for controlling their emissions. This greatly reduces highly toxic diesel particles.

      Amount of sulfur contained in                    Amount of sulfur contained in

          ultra-low sulfur diesel                                   low sulfur diesel

Diesel vehicles usually get better fuel mileage than gasoline vehicles. However, until now, diesel vehicles have not had to meet the same strict air quality standards as gasoline vehicles. Using ULSD fuel will enable diesel vehicles to meet stricter air quality standards while also being more fuel efficient than gasoline vehicles.

Do I have to use ULSD?

If you have a 2007 or newer diesel highway vehicle, you must refuel only with ULSD. For 2006 and older vehicles, there will be a period of transition. These vehicles can use either ULSD or low sulfur diesel during the transition period. Starting December 1, 2010, all diesel vehicles no matter what the model is, year must use ULSD.

Do these requirements apply to commercial vehicles like semi-trucks?


What about trains, boats, and non-road diesel equipment?

Locomotive, marine and non-road diesel fuel engines (such as farm and construction equipment) will also need to use ULSD. However, they will start using it in 2012.

Where and when can I get ULSD?

In western Washington: Most retailers in western Washington will have ULSD for sale by September 2006. However, EPA does not require all service stations or truck stops to sell ULSD right away. A diesel seller may choose to sell low sulfur diesel fuel instead of ULSD fuel until December 1, 2010.

In eastern Washington: Although Ecology expects ULSD to be available in eastern Washington by September 2006, it is possible ULSD may be more difficult to find in eastern Washington for a short time. This is because eastern Washington gets most of its fuel from refineries in the Rocky Mountain region. Because the Rocky Mountain region has less ozone pollution than other areas, EPA is allowing refiners in that region to phase in ULSD production more gradually.

Will ULSD cost more?

EPA estimates that ULSD will cost four to five cents more per gallon to produce. Because it costs more to produce, it will probably cost more at the pump. However, EPA estimates that the reduction in air pollution from ULSD will save us about $70 billion in health benefits, nationally.

How will I know which pumps have ULSD fuel?

Check the pump labels. All diesel fuel pumps must say what kind of fuel they dispense.

Will using ULSD affect my vehicle’s performance?

Although engine and vehicle manufacturers expect ULSD fuel to work fine with existing vehicles, some older vehicles may have problems with fuel system leaks or fuel filter plugging. Check your vehicle’s fuel system often to avoid these problems. Your vehicle may also get slightly less fuel mileage than it did with low sulfur diesel, but there should not be any effect on the vehicle’s overall power.

What if I don’t want to use ULSD in my new car?

2007 and newer diesel vehicles are designed to run only on ULSD fuel. If you use a fuel other than ULSD, you could permanently damage the vehicle. Using the wrong fuel will also cancel manufacturer warranties. In addition, using low sulfur diesel fuel in 2007 and newer vehicles is illegal, and you could be fined.

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