Combustível Energia Content
Comparing Gasoline, Diesel, e Outro Fuels
Compare FuelsPor que does a diesel truck get better mileage than a gasoline one? Por que do electric cars use "MPGe" instead of MPG? O answer lies in energy content—diferente fuels pack diferente amounts of energy per gallon, pound, ou cubic foot. Understanding fuel energy content helps compare vehicles, heating systems, e energy costs.
Liquid Fuels Energia Content
| Combustível | BTU/Gallon | MJ/Liter | kWh/Gallon |
|---|---|---|---|
| Gasoline (regular) | 120,286 | 34.2 | 33.4 |
| Gasoline (premium) | 121,463 | 34.5 | 33.7 |
| Diesel (#2) | 137,381 | 38.6 | 38.2 |
| Biodiesel (B100) | 126,206 | 35.7 | 37.0 |
| Ethanol (E100) | 84,530 | 23.4 | 24.8 |
| E85 (85% ethanol) | 90,660 | 25.6 | 26.6 |
| Propane (LPG) | 91,502 | 25.4 | 26.8 |
| Heating oil | 138,500 | 38.7 | 40.6 |
| Jet fuel (Jet A) | 128,100 | 35.0 | 37.5 |
Gaseous Fuels Energia Content
| Combustível | BTU/Unidade | MJ/Unidade | kWh/Unidade |
|---|---|---|---|
| Natural gas (per therm) | 100,000 | 105.5 | 29.3 |
| Natural gas (per CCF) | 103,000 | 108.7 | 30.2 |
| Natural gas (per cubic ft) | 1,030 | 1.09 | 0.302 |
| Propane (per gallon) | 91,502 | 96.5 | 26.8 |
| Hydrogen (per kg) | 134,000 | 141.4 | 39.3 |
| Compressed natural gas (GGE)* | 120,000 | 126.6 | 35.2 |
*GGE = Gasoline Gallon Equivalente
Solid Fuels Energia Content
| Combustível | BTU/lb | MJ/kg | kWh/kg |
|---|---|---|---|
| Anthracite coal | 12,000-13,000 | 30-32 | 8.3-8.9 |
| Bituminous coal | 10,500-12,500 | 26-31 | 7.2-8.6 |
| Sub-bituminous coal | 8,000-10,000 | 20-25 | 5.6-6.9 |
| Lignite | 5,000-7,000 | 12-17 | 3.3-4.7 |
| Wood (air dried) | 6,400 | 15 | 4.2 |
| Wood pellets | 8,000 | 18.6 | 5.2 |
Por que Energia Content Matters
Vehicle Combustível Eficiência
A diesel vehicle getting 35 MPG actually travels further per BTU than a gasoline car at 30 MPG:
- Diesel: 35 miles ÷ 137,381 BTU = 0.000255 miles/BTU
- Gasoline: 30 miles ÷ 120,286 BTU = 0.000249 miles/BTU
O diesel é 2.4% mais efficient per unidade of energy, not apenas per gallon.
Heating Cost Comparison
Para deliver 1 million BTU of heat:
| Combustível | Amount Needed | Cost* |
|---|---|---|
| Natural gas | 10 therms | ~$12 |
| Propane | 10.9 gallons | ~$33 |
| Heating oil | 7.2 gallons | ~$29 |
| Electricity | 293 kWh | ~$35 |
*Approximate 2024 prices, varies by region
Energia Densidade Comparison
Energia density (energy per unidade weight) affects o que fuels são prático for diferente uses:
| Combustível | MJ/kg | Usar Case |
|---|---|---|
| Hydrogen | 142 | Highest by weight; hard to store |
| Gasoline | 46 | Cars, aircraft |
| Diesel | 45 | Trucks, ships, generators |
| Jet fuel | 43 | Aircraft |
| Natural gas | 55 | Heating, power plants |
| Lithium battery | 0.5-1 | EVs (low energy density) |
Batteries store ~50× menos energy per kg than gasoline—por que EVs need heavy battery packs.
Converting Entre Fuels
Gasoline Gallon Equivalents (GGE)
| Combustível | Amount = 1 GGE |
|---|---|
| Gasoline | 1 gallon |
| Diesel | 0.88 gallons |
| Ethanol (E100) | 1.42 gallons |
| E85 | 1.33 gallons |
| Propane | 1.31 gallons |
| Natural gas | 126.67 cubic feet |
| Electricity | 33.7 kWh |
Conclusão
Diferente fuels contain vastly diferente amounts of energy. Diesel packs sobre 14% mais energy per gallon than gasoline; ethanol tem sobre 30% menos. Understanding estes differences helps you compare fuel costs, vehicle efficiency, e heating options on an igual energy basis rather than apenas price per gallon.