What Is ULSD?
ULSD stands for "Ultra-Low Sulfur Diesel." ULSD is a refined diesel fuel that has dramatically lower sulfur content compared to traditional on-highway diesel fuel. Current on-highway diesel is sometimes called "Low Sulfur Diesel" (LSD). The maximum concentration of sulfur allowed in "low sulfur" fuel is 500 parts per million (ppm). This limit was mandated by the government in 1993. For ULSD, the maximum concentration of sulfur allowed is only 15 ppm, a 97% reduction in sulfur content.

The lower sulfur content of ULSD means fewer sulfate emissions. It also enables the use of emissions reduction equipment such as particulate filters and catalytic converters to lower emissions of Particulate Matter (PM) and Oxides of Nitrogen (NOx). These systems, together with Ultra-Low Sulfur Diesel, can reduce emissions of fine particulates by more than 90 percent and emissions of hydrocarbons to nearly undetectable levels.

Why Is The EPA Driving The Introduction Of ULSD?
ULSD was mandated by EPA as part of the 2007-2010 emissions regulations for heavy-duty engines. It is considered a "technology enabler," allowing the use of catalyst-based emission technologies on MY2007 and later heavy-duty engines, as well as on Tier 2-compliant light-duty diesel vehicles. In other words, the 2007 emissions regulations on diesel engines are driving the use of catalyst-based emission control devices, such as diesel particulate filters and NOx adsorbers. These devices are sensitive to sulfur, so the EPA is changing the on-highway diesel fuel regulations to lower the sulfur content in diesel fuel prior to the emissions regulations going into effect.

When Will ULSD Be Available?
The ULSD implementation schedule is as follows:
June 2006: Refinery level and importers.
September 2006: Terminal level (downstream of the refinery/importer, except for retail outlets and wholesale consumers)
October 15, 2006: Retail level (including wholesale consumers)

All major truck stops and over 95% of all on-road diesel fuel retailers are expected to meet the 15-ppm ULSD standard by October 15, 2006, and most locations will only carry ULSD. At locations which carry both LSD and ULSD, the fuel pumps will be clearly labeled.

Because the task of changing all the diesel fuel in the U.S. on-highway distribution system is complex, and there are multiple flexibility provisions in the mandated schedule, it is not possible to predict precisely when ULSD will become available at the retail level for a given location.

ULSD fuel is backwards compatible, and can be used in all engines.

What Can I Expect With Regards To Maintenance And Fuel Economy?
In general, the processing required to reduce sulfur to 15 ppm also reduces the aromatics content and density of diesel fuel, resulting in a slight reduction in energy content (BTU/gal). The expected reduction in energy content is only approximately 1%.

No impact to fuel filter service intervals is expected.

The same water-drain maintenance practices that are currently followed for fuel filters should also be continued.

A new CI-4 engine oil is being introduced, with a new formulation designed specifically to work with ULSD fuel. If you run with a pre-2007 engine oil (such as CH-4) and ULSD fuel, you will have to modify your oil change schedule.

©2006 Cummins Inc., Direct Marketing, Mail Code 60610, 500 Jackson Street, Columbus, IN 47201 U.S.A.

However, earlier this year DaimlerChrysler also approved the use of B20 biodiesel fuel in its 2007 model year Dodge Ram pickup trucks, but only in certain applications. B20 is a blend of 20-percent biofuel and 80-percent regular diesel fuel. Currently, the B20 blend is only approved for government, military and commercial vehicle use. The approval applies to biodiesel fuel that meets the fuel specifications established by the United States military, which requires the fuel be used within six months of delivery. DaimlerChrysler is the first U.S. automaker to specifically approve the use of B20 in its warranty statements.

DaimlerChrysler and Cummins are working with the government, automotive suppliers, energy providers, universities and independent agencies on a national standard that could make B20 an option for all Dodge Ram diesel owners.

©2006 Cummins Inc., Direct Marketing, Mail Code 60610, 500 Jackson Street, Columbus, IN 47201 U.S.A.