Diesel is not one fuel—it’s several.
Most North American fleets think of diesel as the standard pump product at truck stops, but the global market recognizes multiple grades, each with its own refining requirements, performance characteristics, and pricing behavior. Understanding these distinctions helps fleets avoid misfuelling, manage seasonal performance, and navigate the complex pricing structures that shape the North American fuel market.
Below is a breakdown of the diesel types most relevant to trucking today.
ULSD (Ultra‑Low Sulfur Diesel)
The on‑highway standard across the United States and Canada since 2010, ULSD contains no more than 15 ppm sulfur. It is refined at US and Canadian facilities and distributed through national pipelines and terminals. ULSD is required for all modern emissions‑controlled trucks equipped with SCR systems and diesel particulate filters.
No. 1 Diesel
A lighter distillate with improved cold‑flow properties, No. 1 diesel is commonly blended with No. 2 diesel during the winter months. It is used in extreme cold regions and in equipment that must start reliably in sub‑zero temperatures. The trade‑off is slightly lower energy content, which can reduce fuel economy.
No. 2 Diesel
The standard distillate is used for most trucking applications. No. 2 diesel offers higher energy content than No. 1 diesel and is the primary fuel sold at truck stops across North America.
EN590 Diesel
The European diesel specification is capped at 10 ppm sulfur and blended with up to seven percent biodiesel. EN590 differs from ULSD in cetane rating, cold‑flow requirements, and blending rules. While not commonly used in North America, EN590 influences global diesel markets because Europe is a major importer and exporter of refined distillates.
Biodiesel (B5–B20 blends)
A blend of petroleum diesel and fatty‑acid methyl esters (FAME). Biodiesel is common in municipal fleets and some regional markets but is less favored in long‑haul trucking due to cold‑flow limitations and storage‑stability concerns. Blends vary by region and season.
Renewable Diesel (RD or HVO)
A hydrotreated renewable fuel chemically similar to petroleum diesel. Renewable diesel offers excellent cold‑flow performance and high cetane ratings, and it is increasingly used in California and western states where low‑carbon regulations apply. Unlike biodiesel, RD is fully compatible with diesel engines and does not carry the same winter‑performance limitations.
Where Diesel Is Refined And Why It Matters
North American diesel production is concentrated in several key refining regions, each playing a distinct role in supplying trucking, agriculture, and industrial markets.
The US Gulf Coast is the continent’s largest diesel‑producing region, supplying a significant share of the fuel consumed across the eastern and central United States. Its scale and export capacity often influence national pricing and availability.
Midwest refineries support agricultural states and regional freight corridors, becoming especially important during planting and harvest seasons when diesel demand spikes.
On the West Coast, refineries in California, Oregon, and Washington produce both ULSD and renewable diesel to meet the region’s unique fuel standards. Limited pipeline connections and strict environmental regulations make West Coast diesel markets more expensive and more sensitive to supply disruptions.
Internationally, EN590 diesel is refined in Europe, the Middle East, and Asia before being shipped to global markets. Differences in refining capacity, regional standards, and transportation logistics create price variations between ULSD, EN590, and marine distillates—variations that influence North American diesel prices when global supply tightens.
Do Different Diesel Types Cost Different Amounts?
Yes. Pricing varies based on sulfur content, refining complexity, blending requirements, and regional demand. OPIS market data shows that ULSD, low‑sulfur diesel, dyed off‑road diesel, and marine distillates all trade at different rack and spot prices depending on region and season.
Renewable diesel typically carries a premium due to production costs and regulatory credits, while biodiesel blends may be cheaper or more expensive depending on feedstock markets.
Global conflicts affect diesel prices through several mechanisms:
- Crude oil supply disruptions reduce available feedstock and raise global distillate prices.
- Shipping route instability increases freight costs for imported diesel and distillate cargoes.
- Refinery outages and sanctions tighten global supply when facilities shut down or exports are restricted.
- Market volatility drives futures prices higher as traders price in risk and uncertainty.
These pressures directly influence the cost of ULSD at US truck stops, contributing to the elevated and unpredictable prices fleets have faced in recent years.
Why Understanding Diesel Types Matters For Fleets
For technicians, fleet managers, and operators, knowing the differences between diesel types is essential for ensuring emissions‑system compatibility, managing cold‑weather performance, understanding regional price differences, evaluating renewable‑fuel options, and planning for supply disruptions.
Diesel may be a single word, but it represents a complex global market that directly affects the cost of moving freight across North America.