Answers to frequently asked questions about ULSD fuel.

Q. Where can I purchase ULSD fuel?

A. Although ULSD fuel will be the dominant highway diesel fuel produced, EPA does not require service stations and truck stops to sell ULSD fuel. Therefore, it is possible that ULSD fuel might not be available initially at every service station or truck stop and that a diesel retailer may choose to sell Low Sulfur Diesel fuel instead of ULSD fuel. The industries involved in the transition are doing all they can to minimize potential inconveniences during the conversion to the new diesel fuel.

Q. May I continue to purchase Low Sulfur Diesel fuel if I prefer to use it in my older vehicle?

A. Owners of 2007 and later model year diesel-powered highway vehicles must refuel only with ULSD fuel.* Owners of 2006 and earlier model year diesel-powered engines and vehicles may use ULSD or Low Sulfur Diesel fuel during the transition period. Only ULSD fuel will be available for highway use starting on December 1, 2010.

Q. How will I know which pump is dispensing ULSD fuel?

A. Federal regulations require the labeling of all diesel fuel pumps to specify the type of fuel dispensed by each pump (except in California where all diesel fuel must be ULSD by June 1, 2006). Similar instrument panel and fuel inlet/fill cap labeling is being mandated for 2007 and later model year engines and vehicles that require ULSD fuel. Consumers are advised to check the pump labels and vehicle labels to ensure they are refueling with the proper diesel fuel consistent with their vehicle warranties. Click here for downloadable pump labels in TIF, JPG and EPS formats.

Q.Will ULSD and LSD fuels differ in appearance?

A. The refining process that removes the sulfur can cause ULSD fuel to generally look lighter in color and possibly have a colored tint. ULSD fuel may have less odor than other diesel fuels due to the reduced sulfur content. Changes in color and smell will not impact the performance of ULSD fuel. ULSD and LSD fuels for non-taxable use may be dyed red, similar to today’s non-road diesel fuel. These possible changes in appearance also might be noticed in LSD fuel, as downgraded ULSD fuel can be sold as LSD fuel.

Q. Are all model year 2007 vehicles required to use ULSD?

A. All model year 2007 light-duty passenger diesel-powered vehicles are required to use ULSD fuel, but some medium-duty and heavy-duty diesel-powered model year 2007 vehicles are built with 2006 model year engines that are not equipped with sulfur-sensitive advanced emission control systems. These vehicles do not require ULSD fuel and EPA does not require that these vehicles be fueled with ULSD fuel. Letters from EPA to the American Trucking Associations and Engine Manufacturers Association address this issue in more detail.

Vehicles that require ULSD fuel have specific labels on the dashboard and near the fuel inlet indicating that they must be fueled with ULSD fuel. Vehicles without these labels may be refueled with Low Sulfur Diesel (LSD) or ULSD fuel. Also check the owner’s manual for which fuel your vehicle is required to use.

Q. How will ULSD fuel affect air quality?

A. ULSD fuel will enable the use of cleaner technology diesel engines and vehicles with advanced emissions control devices, resulting in significantly improved air quality. Annual emission reductions will be equivalent to removing the pollution from more than 90 percent of today’s trucks and buses, when the current heavy-duty vehicle fleet has been completely replaced in 2030.

Q. May I continue to blend No. 1 diesel (kerosene) with my diesel fuel to improve cold weather performance?

A. Only ultra low sulfur kerosene (No. 1 diesel with no more than 15 ppm sulfur) may be blended with ULSD fuel to improve cold weather performance. With so many kerosene formulations on the market, care must be taken to select kerosene with a maximum of 15 ppm sulfur. Blend rates will remain the same as with Low Sulfur Diesel fuel.

Q. Will ULSD fuel be more expensive than the current Low Sulfur Diesel fuel?

A. ULSD fuel costs more to refine and distribute than Low Sulfur Diesel fuel. No one can predict with certainty the price of ULSD fuel at the pump. Many factors affect the consumer price of fuels, including the price of crude oil on the global market, geopolitical, weather, transportation and economic events, as well as supply and demand. Visit the Energy Information Administration web site for more information on fuel prices.

Q. How will ULSD fuel affect the power and fuel economy of existing diesel cars, trucks and non-road engines and equipment?

A. Under typical operating conditions, there should be no noticeable impact on overall power using ULSD fuel.* Fuel economy may be reduced slightly because the process that removes sulfur also can reduce the energy content of the fuel.*

Q. Will ULSD fuel affect the performance of my vehicle?

A. Engine and vehicle manufacturers expect ULSD fuel to be fully compatible with the existing fleet, including 2006 and earlier model year vehicles. In some instances, the introduction of ULSD fuel to older vehicles may affect fuel system components or loosen deposits in fuel tanks. As part of a good maintenance program, owners and operators of existing cars, trucks and buses are encouraged to monitor their diesel-powered vehicles closely for potential fuel system leaks or premature fuel filter plugging during the change-over to ULSD fuel.

Q. Can Low Sulfur Diesel fuel be burned without operational problems in 2007 model year and later cars and trucks?

A. Diesel-powered engines for 2007 and later model year highway vehicles are designed to operate only with ULSD fuel. Improper fuel use will reduce the efficiency and durability of engines, permanently damage advanced emissions control systems, reduce fuel economy and possibly prevent the vehicles from running at all.* Manufacturer warranties are likely to be voided by improper fuel use. Additionally, burning Low Sulfur Diesel fuel in 2007 and later model year diesel-powered cars, trucks and buses is illegal and punishable with civil penalties.*

Q. Will I need to put an additive in my fuel tank to replace the lubricity that was provided by the higher sulfur content?

A. Like Low Sulfur Diesel fuel, ULSD fuel requires good lubricity and corrosion inhibitors to prevent unacceptable engine wear. As necessary, additives to increase lubricity and to inhibit corrosion will be added to ULSD fuel prior to its retail sale. With these additives, ULSD fuel is expected to perform as well as Low Sulfur Diesel fuel.

Q. What are the penalties for failing to comply with EPA's ULSD fuel standards?

A. The new standards provide strong incentives for suppliers to provide the proper ULSD fuel formulation. Civil penalties of up to $32,500 per violation per day can be assessed for non-compliance with EPA’s ULSD fuel standards, or for misrepresentation of the sulfur level of diesel fuel. For more information about ULSD fuel standards and implementation, visit:

U.S. Environmental Protection Agency

To submit other questions or requests, please register and fill out the form on the Media Room page, or call 866-406-FUEL (866-406-3835).

*Exception – Some 2007 model year medium-duty and heavy-duty trucks may be equipped with 2006 engines and emission systems. These vehicles are not required to use ULSD fuel.

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