The price of fuel, particularly diesel, is subject to a complex and ever-changing supply chain. Diesel prices jumped up and down by 20% over a few months in 2023 alone, thanks to innumerable shifts in supply and demand.
How fuel prices affect fleets
Fuel is one of the most expensive factors in running a fleet.
From 2014 to 2023, fuel prices made up 24% of a motor carrier’s per-mile operating costs, according to the American Transportation Research Institute. Costing roughly 55 cents per mile, it is the second highest per-mile cost for carriers—surpassed only by driver wages, which averaged 78 cents per mile.
Trucking is one of the largest sources of diesel demand. The U.S. transportation sector—including trucks, trains, boats, and barges—consumed about 125 million gallons of diesel per day in 2022, according to EIA. Transportation that year accounted for 75% of the nation’s total diesel consumption and 15% of its total petroleum consumption. With trucks moving most of the nation’s freight, motor carriers make up a significant share of national diesel demand.
Taxes
On average, state and federal taxes make up about 15% of diesel’s pump price.
Federal fuel taxes have remained unchanged since 1993: The government charges 24.4 cents per gallon of diesel fuel.
State taxes, however, vary. Each state adds its own taxes and fees to a gallon of fuel. A state’s tax can be either a percent of the sales price or a flat per-gallon charge.
According to EIA, in January 2025, the average diesel state diesel fuel tax was about 35 cents per gallon; the highest state tax was California’s at 92 cents per gallon; and the lowest state tax was Alaska’s at about 9 cents per gallon.
Taxes are not the only way that governments influence fuel prices. Environmental regulations, national strategic reserves, and international trade policies can disrupt any part of diesel’s supply chain, further changing costs.
Market speculation
“Supply and demand” is a simple phrase but underrepresents an important part of fuel pricing. Market sentiments and perceived risk play a large part in costs across every step of oil production and distribution.
The perceived values involved in crude oil trading can significantly influence oil prices and, subsequently, the price at the pump. The two major crude oil indicators are the prices of West Texas Intermediate Crude Oil futures and Brent Crude Oil futures.
A common perception is that geopolitical events raise fuel prices. This is particularly common when oil-producing countries are involved. Russia’s invasion of Ukraine caused crude oil prices to rise by upwards of 50%, according to authors in Humanities and Social Sciences Communications. This contributed to skyrocketing fuel prices in 2022 which caused carriers’ operational expenses to jump by 21%.
WTI and Brent prices tend to spike after major conflicts because players in the oil market fear for the future availability of oil, thereby driving demand, according to authors in the Journal of Futures Markets.
However, that spike does not remain for long. Authors writing for the European Central Bank found that Brent prices returned to normal after eight weeks of Russia’s invasion. The ECB authors found that, in the long term, oil prices often remained weak after demand dampened.
How to follow fuel prices
Fleet executives may monitor fuel prices at their most frequent fueling stations or monitor national prices to make strategic business decisions. Every fueling station has its own way of determining prices but tends to follow regional trends.
EIA and AAA are two popular groups reporting regional and national pricing trends. Both organizations publish regular gas and diesel pricing updates. FleetOwner covers weekly pricing trends both nationally and by region.
For particular stations, several technology companies can empower fleets to track diesel prices at specific pumps or along key routes.
