When one litre of petrol is burned, it creates approximately 2.31 kg of carbon dioxide. A litre of fuel, which weighs roughly 840g, emits considerably more carbon dioxide 2.68kg. CO2 is a strong greenhouse gas that is produced during the combustion process in your engine.
Your fuel economy is linked to the quantity of CO2 you emit when driving. The more fuel you consume per km, the more carbon dioxide you produce per kilometre, and car manufacturers frequently provide this statistic. For example, a Ford Ranger with a combined fuel economy of 8.3-8.8 litres per 100km produces between 218 and 230g/km.
We must look at the chemistry to understand why the total carbon dioxide created is heavier than the starting litre of fuel: Although diesel and gasoline are high in carbon, carbon is rather light. When the fuel is burned, the carbon joins with two oxygen molecules (both heavier than the carbon) to form carbon dioxide. Each oxygen molecule is approximately 25% heavier than a carbon molecule, and there are two of them!
To put it in numerical terms, one molecule of carbon weighs 12 grams, while two molecules of oxygen weigh 32 kg!
But what percentage of diesel and gasoline is carbon? About 720g of the 840g that one litre of fuel weighs is carbon. Around 640g of the 740g that one litre of petrol weighs is carbon.
How much CO2 does a gasoline car emit?
- How much carbon dioxide (CO2) is released into the atmosphere when one gallon of gasoline is burned?
- How much carbon dioxide (CO2) does a typical passenger vehicle emit on an annual basis?
- A typical passenger vehicle emits approximately 4.6 metric tons of CO2 each year.
- This estimates that the average gasoline vehicle on the road today gets 22.0 miles per gallon and travels roughly 11,500 miles per year. When a gallon of gasoline is burned, it produces approximately 8,887 grams of CO2.
- Automobiles emit methane (CH4) and nitrous oxide (N2O) through the exhaust, as well as hydrofluorocarbon emissions from leaking air conditioners, in addition to carbon dioxide (CO2). These gases have a larger global warming potential (GWP) than CO2, hence their emissions are minor compared to CO2. However, their impact can be significant because they have a higher GWP than CO2.
- What do a plug-in hybrid electric vehicle (PHEV) or an electric car (EV) emit at the tailpipe? What about hydrogen-fueled automobiles?
- A car that runs entirely on electricity (EV) produces no emissions from the tailpipe. A hydrogen-fueled fuel cell car will solely emit water vapor.
- The calculation of PHEV tailpipe emissions is more difficult. PHEVs can run entirely on electricity, or on a combination of electricity and gasoline. A PHEV that runs solely on electricity (like an EV) produces no exhaust emissions. When a PHEV runs only on gasoline, tailpipe emissions are calculated based on the PHEV’s gasoline fuel economy. Without precise information on how the PHEV operates, tailpipe emissions for a PHEV that runs on both electricity and gasoline cannot be computed. The overall exhaust emissions of a PHEV can vary greatly depending on the battery capacity, how the vehicle is operated, and how frequently it is charged.
- Other than what comes out of the tailpipe, are there any greenhouse gas emissions linked with the operation of my vehicle?
- The majority of vehicles emit greenhouse gases through their tailpipes. Greenhouse gases are produced during the production and distribution of the fuel that powers your car. To make gasoline, for example, oil must be extracted from the ground, transported to a refinery, refined into fuel, and then transported to service stations. Each of these steps has the potential to increase greenhouse gas emissions.
- Although electric vehicles (EVs) have no tailpipe emissions, emissions are produced during the generation and distribution of the electricity used to power them. To calculate GHG emissions for an EV in your area, use the Beyond Tailpipe Emissions tool.
- I was under the impression that my gasoline contained ethanol. Does this have an impact on my CO2 emissions from my tailpipe?
- The majority of gasoline sold in the United States is a blend of gasoline and up to 10% ethanol (often referred to as E10). The actual composition of the gasoline in your vehicle varies depending on the season, region of the United States, and other things. While the fuel economy of an ethanol blend will be somewhat lower than that of gasoline without ethanol, the CO2 tailpipe emissions per mile will be comparable. This is due to the fact that ethanol has a lower carbon footprint per gallon than gasoline.
- The EPA and automakers use a series of standardized laboratory procedures to determine vehicle fuel efficiency and CO2 emissions. The EPA created these tests to replicate common driving habits. These figures are used by the Environmental Protection Agency and the Department of Transportation to ensure that manufacturers meet federal greenhouse gas and corporate average fuel economy (CAFE) regulations.
- The test findings are used to establish real-world fuel efficiency and CO2 emissions for each new car. The Fuel Economy and Environment Labels, as well as Fueleconomy.gov, use these corrected data.
- Click on “Find a Car” at Fueleconomy.gov. Select the “Energy and Environment” tab from the car search results page. The rate of greenhouse gas emissions (g/mile) and GHG rating of a vehicle can be found there.
- Check tailpipe CO2 emission rates on car Fuel Economy and Environment Labels when buying at a dealership. To make comparison shopping easier, the labels include a 1-to-10 Fuel Economy and Greenhouse Gas Rating.
- Where can I find information on the transportation sector’s overall emissions?
- Carbon Pollution from Transportation has documents on greenhouse gas emissions.
- In the study “Light-Duty Automotive Technology, Carbon Dioxide Emissions, and Fuel Economy Trends,” the EPA also publishes industry-wide data. From 1975 to the present, this paper examines trends in fuel efficiency and CO2 emissions for new light-duty vehicles.
What is the carbon content of a litre of gasoline?
Diesel weights 835 grams per liter. Diesel contains 86.2% carbon, or 720 grammes of carbon per liter of diesel. 1920 grammes of oxygen are required to convert this carbon to CO2. The total CO2/liter diesel is then 720 + 1920 = 2640 grammes.
5 l x 2640 g/l / 100 (per km) = 132 g CO2/km equates to 5 l x 2640 g/l / 100 (per km) = 132 g CO2/km.
One liter of gasoline weighs 750 grams. Petrol has an 87 percent carbon content, or 652 grammes of carbon per liter. 1740 grammes of oxygen are required to convert this carbon to CO2. The total is 652 + 1740 = 2392 grammes CO2/liter of gasoline.
5 l x 2392 g/l / 100 (per km) = 120 g CO2/km equates to 5 l x 2392 g/l / 100 (per km) = 120 g CO2/km.
LPG weights 550 grams per liter. LPG has an 82.5% carbon content, or 454 grammes of carbon per liter of LPG. 1211 grammes of oxygen are required to convert this carbon to CO2. The total CO2/liter of LPG is then 454 + 1211 = 1665 grammes.
5 l x 1665 g/l / 100 (per km) = 83 g CO2/km equates to 5 l x 1665 g/l / 100 (per km) = 83 g CO2/km.
CNG (compressed natural gas) is a gaseous fuel that is held under high pressure. As a result, consumption can be represented in both Nm3/100km and kg/100km. Under normal conditions (1 atm and 0 “‘ C), Nm3 stands for a cubic meter. However, the most common unit of measurement for natural gas vehicle consumption is kilograms per 100 kilometers.
In Belgium, there are several types of natural gas, usually grouped into two categories: low and high calorific gas (L- and H-gas). CO2 emissions differ between the two groups and are highly dependent on the gas’s composition and origin. As a result, the calculations below are simply indicative. In Belgium, public CNG stations mostly provide low-calorie gas. As you can see, CO2 emissions per kilogram of H-gas are larger than those of L-gas. However, because H-gas has greater energy, you’ll require less gas every 100 km, ensuring that, at least in theory, the average CO2 emissions from CNG vehicles are unaffected by the type of gas used.
Carbon makes up 61,4 percent of L-gas, or 614 grammes of carbon per kilogram of L-gas. 1638 grammes of oxygen are required to convert this carbon to CO2. The total CO2/kg of L-gas is then 614 + 1638 = 2252 grammes.
5 kg x 2252 g/kg = 113 g CO2/km corresponds to an average usage of 5 kg per 100 km.
Carbon accounts for 72,7% of H-gas, or 727 grammes of carbon per kilogram of H-gas. 1939 grammes of oxygen are required to convert this carbon to CO2. The total CO2/kg of H-gas is then 727 + 1939 = 2666 grammes.
4,2 kg x 2666 g/kg = 112 g CO2/km corresponds to an average usage of 4,2 kg per 100 km.
What is the CO2 output per litre of diesel?
Per litre of diesel fuel utilized, diesel engines emit 2.7 kg of CO2. CH4 is a flammable gas that is colorless and odorless. It has a global warming potential of more than 20 times that of CO2 and can last for up to 12 years in the atmosphere.
How much CO2 is released by petroleum?
In 2019, the United States had 120.9 million households (EIA 2020a). Each home used an average of 11,880 kWh of provided power. In 2019, total household consumption of natural gas, liquefied petroleum gas, and fuel oil was 5.23 quadrillion Btu, 0.46 quadrillion Btu, and 0.45 quadrillion Btu, respectively (EIA 2020a). This equates to 41,510 cubic feet of natural gas, 42 gallons of liquefied petroleum gas, and 27 gallons of fuel oil per family in the United States.
In 2019, the national average carbon dioxide output rate for generated energy was 884.2 lbs CO2 per megawatt-hour (EPA 2021), equating to around 953.7 lbs CO2 per megawatt-hour for delivered electricity (assuming 7.3 percent transmission and distribution losses) (EPA 2021; EIA 2020b).
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Natural gas has an average carbon dioxide coefficient of 0.0551 kg CO2 per cubic foot (EIA 2019). The total amount of CO2 oxidized is 100 percent (IPCC 2006).
Distillate fuel oil has an average carbon dioxide coefficient of 431.87 kg CO2 per 42-gallon barrel (EPA 2021). The total amount of CO2 oxidized is 100 percent (IPCC 2006).
Liquefied petroleum gases have an average carbon dioxide coefficient of 235.7 kg CO2 per 42-gallon barrel (EPA 2021). The oxidized percentage is 100 percent (IPCC 2006).
Total CO2 emissions per home were calculated by converting total residential electricity, natural gas, distillate fuel oil, and liquefied petroleum gas consumption from various units to metric tons of CO2.
Calculation
Note that due to rounding, the results of the computations given in the equations below may not be correct.
1. Electricity: 11,880 kWh per home 884.2 lbs CO2 per megawatt-hour generated (1/(1-0.073)) MWh generated/MWh delivered 1 MWh/1,000 kWh = 5.139 metric tons CO2/home
2. Natural gas: 41,510 cubic feet per home = 2.29 metric tons CO2/home 0.0551 kg CO2/cubic foot 1/1,000 kg/metric ton
3. LPG: 42 gallons per home, 1/42 barrels per gallon, 235.7 kg CO2/barrel, 1/1,000 kg/metric ton = 0.23 metric tons CO2/home
4. Fuel oil: 27 gallons each home 1/42 barrels per gallon 431.87 kg CO2/barrel 1/1,000 kg/metric ton = 0.28 metric tons CO2/home
5.139 metric tons CO2 for electricity + 2.29 metric tons CO2 for natural gas + 0.23 metric tons CO2 for liquid petroleum gas + 0.29 metric tons CO2 for fuel oil = 7.94 metric tons CO2 per residence per year.
Sources
- Environmental Impact Assessment (EIA) (2020a). Residential Sector Key Indicators and Consumption, Table A4 of the 2020 Annual Energy Outlook.
- Environmental Impact Assessment (EIA) (2020b). Table A8: Electricity Supply, Disposition, Prices, and Emissions in the 2020 Annual Energy Outlook.
- Environmental Impact Assessment (EIA) (2019). Table A4: Approximate Heat Content of Natural Gas for End-Use Sector Consumption, Monthly Energy Review November 2019. (PDF) (About PDF, 270 pages, 2.65 MB)
- Environmental Protection Agency (EPA) (2021). Greenhouse Gas Emissions and Sinks in the United States, 1990-2019. Tables A-47 and A-53 in Annex 2 (Methodology for Estimating CO2 Emissions from Fossil Fuel Combustion). Washington, DC: US Environmental Protection Agency. #430-R-20-002 (PDF) (US EPA) (96 pp, 2 MB, About PDF)
- Environmental Protection Agency (EPA) (2021). eGRID, yearly national emission factor for the United States, data for 2019. Washington, DC: US Environmental Protection Agency.
- IPCC (Intergovernmental Panel on Climate Change) (2006). The IPCC Guidelines for National Greenhouse Gas Inventories were published in 2006. 2nd Edition (Energy). Geneva, Switzerland: Intergovernmental Panel on Climate Change.
What is the source of the most CO2?
Plants absorb CO2 from the atmosphere as they grow, and some of this carbon is stored as aboveground and belowground biomass throughout their lives. Depending on how the soil is managed and other environmental variables, soils and dead organic matter/litter can also store some of the carbon from these plants (e.g., climate). Biological carbon sequestration refers to the storage of carbon in plants, dead organic matter/litter, and soils. Biological sequestration is often known as a carbon “sink” since it removes CO2 from the atmosphere and stores it in these carbon pools.
CO2 emissions or sequestration, as well as CH4 and N2O emissions, can occur as lands are managed in their current use or changed to different land uses. As cropland is turned to grassland, lands are cultivated for crops, or woods expand, carbon dioxide is exchanged between the atmosphere and the plants and soils on land. Furthermore, using biological feedstocks (such as energy crops or wood) for purposes such as electricity generation, as inputs to liquid fuels production processes, or as construction materials can result in emissions or sequestration.
Land Use, Land-Use Change, and Forestry (LULUCF) activities in the United States have resulted in greater CO2 removal from the atmosphere than emissions. As a result, the LULUCF sector in the United States is seen as a net CO2 sink rather than a supplier. The contrary is true in many parts of the world, particularly in countries where huge portions of forest land are destroyed, frequently for agricultural uses or towns. The LULUCF industry can be a net source of greenhouse gas emissions in these conditions.
- The Land Use, Land-Use Change, and Forestry chapter of the Inventory of U.S. Greenhouse Gas Emissions and Sinks contains more national-level data on land use, land-use change, and forestry. See also the USFS Resource Update for more information on emissions and sequestration from forest land and urban trees in settlement zones.
- See the EPA’s Worldwide Greenhouse Gas Emissions website and the Contribution of Working Group III to the Intergovernmental Panel on Climate Change’s Fifth Assessment Report for further information on global emissions from land use and forestry activities.
* CO2 emissions and sequestration are reported in the Inventory under the Land Use, Land-Use Change, and Forestry sector. Land use and management operations in the LULUCF sector also result in methane (CH4) and nitrous oxide (N2O) emissions. In the Energy sector, there are further emissions from CH4 and N2O.
How much CO2 does an automobile emit every kilometer?
Cars, as we all know, spew Carbon Dioxide into the environment. This adds to air pollution as well as the greenhouse effect, which contributes to global warming. We measure CO2 gas emissions for these two reasons.
According to the UK government, transportation accounts for around a quarter of all greenhouse gas emissions in the country. The EU, on the other hand, claims that road transport accounts for one-fifth of all CO2 emissions, and that it is the only sector in which CO2 emissions are increasing.
As a result, actions are being taken both at home and abroad to minimize the quantity of carbon dioxide created by vehicles. For example, by 2021, the European Union (and the United Kingdom) want all new cars to emit 95 grams of CO2 per kilometer on average. This represents a 40% reduction from the 158.7g/km average emissions for automobiles in 2007.
Meanwhile, the US Environmental Protection Agency claims that road transportation accounts for more than a quarter of the country’s greenhouse gas emissions. Between 2012 and 2025, they want to reduce greenhouse gas emissions from new cars by 6 billion metric tonnes.
How much CO2 is emitted?
- In 2016, we emitted 68.5 MtCO2e (metric tons of carbon dioxide equivalent) – the same amount as in 2015.
- Between 2000 and 2015, total CO2 emissions from all vehicles on the road decreased by 4.6 percent.
CO2 Emissions from new different types of cars:
- A new car emits around 20% less pollution than the average car on the road today. (In 2015, the average car on the road emitted 153.0g/km, whereas a new car emitted only 121.4g/km.)
- Alternatively fuelled vehicles (AFVs), such as hybrid autos, emit about 40% less CO2 than the average car on the road.
Progress in the future?
The quest for efficiency and new production methods continues, with targets set for 2021, so it will be fascinating to observe if emissions continue to fall in the future years.
However, unless there is a drop in the amount individuals use their automobiles, any emission reductions may be outweighed by the growth in car usage (a 7% increase between 2000 and 2015).
How much CO2 is produced by a gallon of gasoline?
Here’s how to do it. The two oxygen atoms make up the majority of the weight of carbon dioxide (CO2) (the O2). Carbon and hydrogen atoms are bonded together in gasoline molecules. The carbon and hydrogen in the gas molecules separate when it burns. H2O, or water, is formed when two hydrogen atoms unite with one oxygen atom.
Each carbon atom in gasoline joins two oxygen atoms already present in the atmosphere. CO2 is the result of this.
Read on if you’re curious about why CO2 is so much heavier than gasoline and enjoy math.
The atomic weight of a carbon atom is 12. This indicates its nucleus (core) has a total of 12 protons and neutrons. The atomic weight of one oxygen atom is 16. As a result, each CO2 molecule has an atomic weight of 44:
So a molecule of CO2 has a total atomic weight of 44, which is 3.7 times greater than the weight of a single carbon atom (44 divided by 12).
The next step is to determine how much of the gasoline’s weight is made up of carbon. By weight, gasoline is made up of around 87 percent carbon and 13 percent hydrogen. So a gallon of gasoline (weighing 6.3 pounds) contains 5.5 pounds of carbon (.87 x 6.3 pounds = 5.5 pounds). So, multiply the weight of the carbon by 3.7, and you’ll have 20 pounds of CO2!
