Diesel vs gasoline price: today's state-by-state spread
Today the US average diesel-over-regular spread is about 65 cents per gallon (regular $3.87, diesel $4.88 [EIA · 13 Jul 2026]). The gap widens in CARB-spec states like California and Washington and narrows along the Gulf Coast where refining capacity for both fuels is densest.
Why diesel is usually above regular
Diesel and gasoline are both distillates of the same crude barrel but they compete for the same refinery output. Three structural drivers explain the spread:
- Year-round demand. Trucking and rail freight buy diesel every week of the year. Gasoline is more seasonal.
- ULSD specification cost. Ultra-low-sulfur diesel (15 ppm) requires hydroprocessing.
- Heating-oil correlation. Northeast No. 2 distillate demand crowds out diesel from October through March.
When did diesel first overtake gasoline?
The 2004-2005 transition to ULSD (mandated 1 June 2006 for on-highway) cemented a structural diesel premium. Before then, diesel was generally cheaper than regular. EIA Today In Energy has tracked the inversion. [EIA · 13 Jul 2026]
2026 outlook
EIA STEO projects diesel will hold a 60-70 cent premium through 2026 as crude eases but refining capacity for distillate stays tight.
Related
All diesel · cheapest diesel on I-80 · heating-oil cross-reference · refining margin