I cannot stand the levels which
@mtgreenee has sunk for a dollar. Who's paying her? Foriegn? If so has she registered? It is time to look into this maniac who lies to the public to get paid.
Here is the truth on diesel. Diesel was cheaper than gasoline for most of the 1980s and 1990s. That relationship flipped in the mid-2000s and has not gone back. Your memory of the old price relationship is right; the idea that diesel is still simply “cheaper to make” is only partly true today.
Through the early 1980s, diesel was typically several cents to 20+ cents cheaper per gallon.
The fact is Crude oil is distilled into fractions by boiling point. Diesel is a middle distillate. A larger share of a typical barrel comes out in that range with less extra chemical conversion than gasoline needs. Gasoline requires more cracking, reforming, and blending to hit octane.
Since 2006, highway diesel in the U.S. must be ultra-low sulfur diesel (ULSD): sulfur capped at 15 parts per million, down from 500 ppm. Stripping that sulfur requires high-pressure hydrotreating — hydrogen, energy, expensive catalysts, and extra capital. Yields drop a bit. Estimates of the added cost commonly fall in the 15–25 cents-per-gallon range, plus the billions refiners spent on equipment before the mandate. That process erased much of diesel’s old manufacturing edge.
So: diesel is still simpler to obtain from the barrel than gasoline. It is no longer simpler or cheaper to finish to legal highway spec.
What actually flipped the price
Three durable forces, plus later shocks that widened the gap.
1. Higher taxes (old, and only part of the story) Federal excise tax is 24.4 cents per gallon on diesel vs. 18.4 cents on gasoline — a 6-cent gap that has existed since the mid-1980s. In 1983 both fuels were taxed more to fund highways. In 1984 Congress cut planned heavy-truck user fees after industry pushback and raised the diesel tax instead, on the theory that trucks do more road damage. Many states also tax diesel at a higher rate.
That tax difference was already in place when diesel was still cheaper at the pump. It explains a slice of today’s premium, not the reversal.
2. ULSD (the manufacturing change)
The 15 ppm sulfur rule, phased in from the mid-2000s and fully in force for highway diesel in 2006, is the main cost-of-making-it change. It also constrained some supply during the transition. EIA lists this as one of the three reasons diesel has stayed above gasoline since 2004.
3. Global demand for middle distillates outran the old U.S. setup
Diesel, heating oil, and jet fuel all come from the same middle of the barrel. From the 2000s onward:
China and India industrialized and moved far more freight.
Europe dieselized a large share of its passenger fleet (tax policy encouraged it).
World shipping, trucking, construction, and agriculture kept growing.
U.S. gasoline demand flattened (better cars, later remote work and EVs), while diesel demand stayed tied to the real economy and to exports.
U.S. refineries were built as gasoline machines. They cannot freely turn the whole barrel into diesel without giving up gasoline and jet fuel. When distillate markets tighten, diesel (and heating oil) jump first. Winter heating-oil demand still shares the same pool, so cold weather still lifts diesel. The U.S. also exports a lot of diesel, so American pump prices track the world distillate market more than the domestic gasoline market.
Later events made the premium larger, not smaller: tight refining capacity after some closures and conversions, the 2022 disruption of Russian diesel exports to Europe, and periodic spikes in freight and industrial demand. The structural floor (ULSD + tax + global distillate tightness) stayed; the spikes stacked on top.
The rest is extra refining cost for clean diesel plus a market in which diesel is the fuel the world needs more of, from a limited slice of every barrel, while U.S. gasoline is relatively well supplied. These are the reasons.
California diesel $8.49 but Georgia is $6.59, both RIDICULOUS!!!
The fuel crisis is only just beginning.