What is ULSD? Ultra-Low Sulfur Diesel Explained
ULSD stands for Ultra-Low Sulfur Diesel — a cleaner-burning diesel fuel containing no more than 15 parts per million (ppm) of sulfur. Since 2006, the EPA has required all on-road diesel sold in the United States to meet the ULSD standard, replacing Low Sulfur Diesel (LSD) which contained up to 500 ppm of sulfur.
How It Relates to Fuel Delivery
ULSD is the standard diesel fuel used in virtually all modern diesel engines, from Class 8 trucks to backup generators to construction equipment. The dramatic reduction in sulfur content — from 500 ppm down to 15 ppm — was mandated to enable advanced emissions control systems like diesel particulate filters (DPFs) and selective catalytic reduction (SCR) systems.
For fleet operators and construction companies, ULSD is simply 'diesel' — it's the only on-road option available at terminals and fuel distributors. Off-road applications may use dyed diesel, which is also ULSD but carries a red dye to indicate it hasn't been taxed for on-road use.
ULSD has better lubricity characteristics when properly treated with additives, and it's compatible with biodiesel blends up to B20 in most modern engines. BettyJet sources ULSD from major terminals across Florida and delivers it in quantities from 500 gallons to full transport loads.
Why It Matters for BettyJet Customers
When you order diesel from BettyJet, you're getting ULSD that meets or exceeds all EPA and ASTM D975 specifications. We source from multiple Florida terminals to ensure consistent quality and competitive pricing, whether you need 500 gallons for a generator or 8,000 gallons for a fleet yard.
Frequently Asked Questions
Is ULSD the same as regular diesel?
Yes — since 2006, all on-road diesel sold in the U.S. is ULSD (ultra-low sulfur diesel) with 15 ppm or less sulfur. When you buy 'diesel' or '#2 diesel,' you're buying ULSD.
Can I use ULSD in older diesel engines?
ULSD is compatible with all diesel engines. However, older engines built before 2007 may not have the advanced emissions systems that ULSD was designed to protect. ULSD works fine in these engines — it just won't cause harm to existing components.
Related Terms
Dyed diesel — also called red diesel or off-road diesel — is standard ULSD fuel that has been dyed red to indicate it is exempt from federal and state road taxes. It is chemically identical to on-road diesel but costs significantly less because the tax (typically $0.40-0.60/gallon) is not applied.
Wet HosingWet hosing is the practice of fueling vehicles or equipment directly from a mobile fuel truck rather than from a stationary storage tank. The fuel truck pulls up to each vehicle and fills it on-site — no bulk tank, no pump, no infrastructure required.
BOLA BOL (Bill of Lading) is the primary shipping document for fuel delivery. It serves as a receipt, a contract of carriage, and a document of title — recording what fuel was loaded, where it came from, and where it's going. Every fuel delivery in the United States requires a BOL.
Ready to Order Fuel?
Get a competitive quote for diesel, gasoline, jet fuel, DEF, or marine fuel delivered anywhere in Florida.