What is Ultra Low Sulfur Diesel?

October 15, 2006 made history in the fight for clean air. The Environmental Protection Agency (EPA)’s initiative to make it a requirement that 80% of diesel fuel available for on-road vehicles be Ultra Low Sulphur Diesel (ULSD) officially took effect, and refiners across the country must now ensure the sulphur in on-road diesel fuel is kept to a maximum of 15 parts per million sulphur content. (15ppm). Ultra Low Sulphur Diesel may smell or appear slightly different than current on-road Low Sulphur Diesel (LSD) which can have up to 500ppm sulphur content. ULSD is a cleaner burning diesel fuel and will reduce emissions from diesel vehicles.
USLD is good for the air we breathe and is cleaner for the environment. It has fewer sulphur oxides which cause acid rain. Moreover, emits 30% less sulphur dioxide whose particulate is a key contributor to global warming. The EPA estimates that nitrogen oxide emissions may be reduced by 2.6 million tons per year, and soot and particulate matter by 110,000 tons per year.

Though ULSD availability became mandatory for all on-road diesel vehicles on October 15, 2006, off-road diesel fuel will be phased in over several years. In 2007 off-road, locomotive and marine diesel fuel must meet the 500ppm LSD specifications. Beginning 2010, off-road diesel fuel will be formulated to ULSD 15ppm except for locomotive and marine fuel which will not move to ULSD until 2012.

ULSD will completely replace the current on-road LSD. It is required for use in 2007 model year engines which will be equipped with advanced emission control systems. These next generation advanced emission control systems cannot tolerate levels of sulphur found in LSD. Engine and vehicle manufacturers expect ULSD to be fully compatible with the existing fleet and anticipate no changes to current equipment in order to operate with the new fuel.
However, the use of ULSD will affect all vehicles in varying degrees. The most vulnerable are pre-1993 engines with original rubber seals and fittings and high mileage vehicles with original fittings. The processes that remove sulphur from diesel fuel reduce lubrication which is essential in protecting various parts of the engine’s fuel injection system from excessive wear. Preventative maintenance is recommended including fuel filters, engine seals and a review of manufacturers ULSD recommendations. Lubricant additives may be needed in some cases.

Expect to pay a bit more for Ultra Low Sulfur Diesel at the pump than for current highway diesel fuel – several cents more per gallon, according to EPA estimates.

The Canadian Petroleum Products Institute reports that the processes that remove sulphur also reduce aromatics and the density of fuel which may lower the energy content per litre, by about 1%. This could result in a decrease in the peak power of the engine, however under typical operating conditions there should be no noticeable impact on the overall power of the vehicle. The reduction in energy content could result in a similar reduction in overall fuel economy.

This information is reprinted with permission from 4Refuel. 4Refuel is a leader in fuel management whose industrial practices and refuelling policies carefully adhere to, or exceed federal regulations. 4Refuel is an environmentally responsible, clean air refueler.

If you have any questions regarding ULSD or about fuel management contact 4Refuel Inc at 1-888-4Refuel.