Diesel
One gallon of diesel burned represents approximately:
What this means
These are physical measurements, not dollar estimates. The combustion value measures the CO₂ released when the fuel is burned. The lifecycle value includes upstream fuel production, refining, transport, distribution, and combustion. For another fossil-energy example, see natural-gas combined-cycle electricity.
Formal measurement basis
| Item measured | Diesel fuel |
|---|---|
| Formal functional unit | 1 U.S. gallon of diesel combusted |
| Metric equivalent | Approximately 3.785 liters of diesel burned |
| Primary boundary | Fuel lifecycle: production, refining, distribution, and combustion |
| Secondary boundary | Combustion-only CO₂ |
| Source review | Version 2 source review, 2026 |
Full measurement table
| Physical quantity | Working value | Literature range | Unit | Boundary note |
|---|---|---|---|---|
| Combustion CO₂ | 22.45 | Point factor | lb CO₂ / gallon | Direct fuel combustion only |
| Lifecycle GHG | ~32.1 | Point estimate pending broader literature range | lb CO₂e / gallon | Fuel lifecycle, using 100.45 gCO₂e/MJ and diesel heat content |
| Upstream GHG only | ~9.6 | Derived from point estimate | lb CO₂e / gallon | Lifecycle GHG minus combustion CO₂ |
| Energy content | 137,380 | Point factor | Btu / gallon | Fuel heat content |
| NOx and particulate matter | Not selected | Application-dependent | varies | Depends on engine, controls, duty cycle, and maintenance |
What is included
The lifecycle working value includes the fuel-cycle boundary: crude recovery, transport, refining, distribution, and final combustion. The combustion-only value includes only the CO₂ released when the diesel is burned.
What is excluded
- Vehicle manufacture
- Road construction
- Infrastructure effects
- Dollar conversion of climate, air quality, or health effects
- Engine-specific NOx and particulate claims unless a specific engine boundary is selected
Why values vary
Combustion CO₂ is relatively stable because it follows from fuel carbon content. Lifecycle GHG values vary with crude source, refining pathway, transport distance, energy inputs, and lifecycle model assumptions. NOx and particulate values vary even more because they are tied to combustion equipment and emissions controls.
Source notes
The direct combustion value comes from EIA's diesel CO₂ coefficient. The lifecycle working value is calculated from a conventional diesel lifecycle carbon intensity and EIA heat content. Upstream GHG is derived by subtracting combustion CO₂ from the lifecycle value. The lifecycle number is a point estimate; a broader literature range should be hardened in a later data pass.
Sources
- U.S. Energy Information Administration, Carbon Dioxide Emissions Coefficients. Used for: 22.45 lb CO₂ per gallon diesel combustion value.
- California Air Resources Board, CA-GREET3.0 Lookup Table Pathways. Used for: conventional California ULSD lifecycle carbon intensity of 100.45 gCO₂e/MJ.
- U.S. Energy Information Administration, Thermal Conversion Factor Source Documentation. Used for: 137,380 Btu per gallon conventional diesel heat content.
- U.S. Environmental Protection Agency, AP-42: Gasoline and Diesel Industrial Engines. Used for: context on engine-dependent NOx and particulate emissions.