- Diesel costs 18% more per gallon than regular gasoline ($3.66 vs $3.10 in 2025), but delivers 25 to 30% better fuel economy.
- On a cost per mile basis, diesel is cheaper to operate across all vehicle classes. A diesel pickup saves roughly $229 per year vs gasoline at 15,000 miles.
- Diesel was cheaper than gasoline through 2004. Since 2005, diesel has carried a persistent $0.30 to $1.00 per gallon premium.
- Diesel passenger cars have disappeared from the U.S. market. Today, diesel is available only in full size pickups and SUVs.
01 Introduction
The diesel vs gasoline comparison often focuses on price per gallon, but that metric is misleading. A gallon of diesel contains roughly 13% more energy than a gallon of gasoline, and diesel engines convert fuel to motion more efficiently. The result: diesel vehicles typically travel 25 to 30% farther on each gallon. The real comparison is cost per mile, not cost per gallon.
DOE Alternative Fuels Data Center: diesel contains ~137,381 BTU/gallon vs gasoline ~120,238 BTU/gallon, a 14.3% energy density advantageThis article compares diesel and gasoline on price, fuel economy, and cost per mile using 26 years of EIA price data and EPA fuel economy ratings. For the broader picture of what driving costs in America, see our overview. All figures come exclusively from U.S. government sources.
EIA Weekly Retail Gasoline and Diesel Prices (annual averages); EPA FuelEconomy.gov vehicle dataset02 Price History: Diesel vs Gasoline
For decades, diesel was cheaper than gasoline at the pump. That relationship reversed in 2005 and has remained inverted ever since. In 2025, No. 2 diesel averaged $3.66 per gallon versus $3.10 for regular gasoline, an 18% premium.
EIA Annual Average Retail Prices: U.S. Regular Gasoline and No. 2 Diesel, 2000 to 2025| Year | Regular Gas | No. 2 Diesel | Diesel Premium |
|---|---|---|---|
| 2000 | $1.51 | $1.49 | +$0.02 cheaper |
| 2005 | $2.30 | $2.40 | +$0.10 |
| 2008 | $3.27 | $3.80 | +$0.53 |
| 2012 | $3.64 | $3.97 | +$0.33 |
| 2016 | $2.14 | $2.31 | +$0.17 |
| 2020 | $2.17 | $2.55 | +$0.38 |
| 2022 | $3.95 | $4.99 | +$1.04 |
| 2025 | $3.10 | $3.66 | +$0.56 |
03 Fuel Economy: Diesel vs Gasoline
Diesel engines consistently deliver better fuel economy than gasoline engines in matched vehicle classes. The advantage ranges from 25% to 30% for trucks and SUVs. EPA test data for model years 2015 through 2026 shows this pattern clearly across the classes where both fuel types are available.
EPA FuelEconomy.gov vehicle dataset, diesel and regular gasoline configurations, model years 2015 to 2026| Vehicle Class | Gas MPG | Diesel MPG | Diesel Advantage |
|---|---|---|---|
| Standard Pickup | 18.2 | 23.6 | +30% |
| Standard SUV | 18.5 | 23.0 | +24% |
| Midsize Sedan* | 32.0 | 40.0 | +25% |
| Compact Car* | 33.0 | 42.0 | +27% |
Estimate your vehicle's driving cost using official EPA fuel economy data.
Use the Calculator04 Cost Per Mile: The Real Comparison
The cost per mile calculation reveals that diesel's fuel economy advantage more than compensates for its higher per gallon price. Even with diesel costing $0.56 more per gallon in 2025, diesel trucks and SUVs are cheaper to fuel per mile than their gasoline equivalents.
Cost per mile = price per gallon / combined MPG. Gas: $3.10/gal; Diesel: $3.66/gal (EIA 2025 annual averages)| Vehicle Class | Gas Cost/Mi | Diesel Cost/Mi | Diesel Savings/Year |
|---|---|---|---|
| Standard Pickup | $0.170 | $0.155 | $229 |
| Standard SUV | $0.168 | $0.159 | $127 |
| Midsize Sedan* | $0.097 | $0.092 | $81 |
| Compact Car* | $0.094 | $0.087 | $102 |
The pickup truck class shows the largest dollar savings because it combines the highest fuel consumption with a substantial 30% diesel MPG advantage. Over 5 years at 15,000 miles per year, a diesel pickup owner saves roughly $1,145 in fuel compared to an equivalent gasoline truck.
5 year savings: $229/year × 5 = $1,145, assuming stable price differential. Actual savings vary with price fluctuations.05 Diesel in the American Fleet
Diesel passenger vehicles have always been a niche in the American market. After a brief peak in the early 1980s (when several manufacturers sold diesel variants of popular sedans), diesel’s share of new vehicle configurations fell below 1% by the late 1990s. A modest revival in the 2010s, driven by imported diesel sedans and domestic truck diesels, pushed the share back to roughly 3% by 2015.
EPA FuelEconomy.gov vehicle dataset: diesel configurations as percentage of all configurations by model yearA major emissions testing scandal in 2015, in which a manufacturer was found to have installed software that cheated on diesel emissions tests, effectively ended the diesel car segment in America. European automakers withdrew their diesel sedans and SUVs from the U.S. market. Today, diesel is available only in full-size half-ton and heavy-duty pickups and a handful of full-size body-on-frame SUVs.
EPA FuelEconomy.gov 2026 model year: diesel configurations limited to Standard Pickup Trucks and Standard Sport Utility VehiclesEstimate your vehicle's driving cost using official EPA fuel economy data.
Use the Calculator06 Data Sources
Every data point in this article comes from a U.S. government source. No proprietary, estimated, or third party data was used.
- U.S. Energy Information Administration (EIA). Annual average retail gasoline prices (regular grade), 2000 to 2025. Weekly Retail Gasoline and Diesel Prices survey.
- U.S. Energy Information Administration (EIA). Annual average retail No. 2 diesel prices, 2000 to 2025. Petroleum and Other Liquids, Retail Prices.
- EPA FuelEconomy.gov Vehicle Dataset. Diesel and regular gasoline configurations, combined MPG averages by vehicle class, model years 2015 to 2026.
- EPA FuelEconomy.gov Vehicle Dataset. All model years 1984 to 2026. Diesel configuration counts and share of total configurations.
- U.S. Department of Energy, Alternative Fuels Data Center. Fuel energy content: diesel 137,381 BTU/gallon, gasoline 120,238 BTU/gallon.