A typical passenger vehicle emits about 4.6 metric tons of carbon dioxide per year. This number can vary based on a vehicle’s fuel, fuel economy, and the number of miles driven per year. Click on the questions below to learn more about this estimate and see answers to common questions about greenhouse gas emissions from passenger vehicles.
- How much tailpipe carbon dioxide (CO2) is created from burning one gallon of fuel?
- CO2 emissions from a gallon of gasoline: 8,887 grams CO2/ gallon
- CO2 emissions from a gallon of diesel: 10,180 grams CO2/ gallon
How can burning one gallon of gasoline produce 8,887 grams (approximately 20 pounds) of tailpipe carbon, when one gallon of gasoline weighs only about six pounds?
Most of the weight of the CO2 doesn’t come from the gasoline itself, but the oxygen in the air. When gasoline burns, the carbon and hydrogen separate. The hydrogen combines with oxygen to form water (H2O), and carbon combines with oxygen to form carbon dioxide (CO2). Visit fueleconomy.gov for more details, including the calculations.
- How much tailpipe carbon dioxide (CO2) is emitted from driving one mile?
- The average passenger vehicle emits about 400 grams of CO2 per mile.
- What is the average annual carbon dioxide (CO2) emissions of a typical passenger vehicle?
- A typical passenger vehicle emits about 4.6 metric tons of CO2 per year.
- This assumes the average gasoline vehicle on the road today has a fuel economy of about 22.2 miles per gallon and drives around 11,500 miles per year. Every gallon of gasoline burned creates about 8,887 grams of CO2.
- Are there other sources of greenhouse gas (GHG) emissions from a vehicle?
- In addition to carbon dioxide (CO2), automobiles using gasoline produce methane (CH4) and nitrous oxide (N2O) from the tailpipe and all vehicles can emit hydrofluorocarbon (HFC) from leaking air conditioners. For gasoline vehicles, the emissions of HFCs are small in comparison to CO2; however, the impact of these emissions can be important because they have a higher global warming potential (GWP) than CO2. Electric vehicles (EVs) also emit a small amount of GHGs due to air conditioner/HFC leakage.
- What are the tailpipe emissions from a plug-in hybrid electric vehicle (PHEV) or an electric vehicle (EV)? What about hydrogen fuel cell vehicles?
- Electric vehicles (EVs) have a battery instead of a gasoline tank, and an electric motor instead of an internal combustion engine. EVs do not emit any tailpipe emissions. A fuel cell electric vehicle (FCEV) operating on hydrogen will emit only water vapor.
- Calculating tailpipe emissions for PHEVs is more complicated because they use both gasoline and electricity as fuel sources. When operating on electricity only, a PHEV does not generate any tailpipe emissions. When a PHEV is operating on gasoline only, it creates tailpipe emissions based on its gasoline fuel economy. Tailpipe emissions for a PHEV operating on both electricity and gasoline cannot be calculated without detailed information about how the specific PHEV operates. The overall tailpipe emissions for a PHEV can vary significantly based on its battery capacity, how it is driven, and how often it is charged.
For more information, see the “My Plug-In Hybrid” calculator.
- Are there any greenhouse gas (GHG) emissions associated with the use of my vehicle other than what comes out of the tailpipe?
- Driving gasoline vehicles results in tailpipe GHG emissions. Producing and distributing the gasoline used to power your vehicle also creates GHGs. For example, the production of gasoline requires extracting oil from the ground, transporting it to a refinery, refining the oil into gasoline, and transporting the gasoline to service stations. Each of these steps can produce additional GHGs.
- Electric vehicles (EVs) have no tailpipe emissions; however, emissions are created during both the production and distribution of the electricity used to fuel the vehicle. Visit the Beyond Tailpipe Emissions calculator to estimate GHG emissions for an EV in your region of the country.
- I thought my gasoline was blended with ethanol. Does that change my tailpipe carbon dioxide (CO2) emissions?
- Most of the gasoline sold in the U.S. is a mixture of gasoline and up to 10% ethanol (often referred to as E10). The exact formulation of the gasoline in your vehicle will vary depending on season, region in the U.S., and other factors. While your fuel economy when using an ethanol blend in your vehicle will be slightly lower than when using gasoline without ethanol, the CO2 tailpipe emissions per mile will be similar. This is because ethanol has less carbon per gallon than gasoline.
- How does EPA measure carbon dioxide (CO2) emissions from vehicles?
- EPA and automobile manufacturers measure vehicle fuel economy and CO2 emissions using a set of standardized laboratory tests. These tests were designed by EPA to mimic typical driving patterns. Both EPA and the Department of Transportation use these values to ensure that manufacturers meet federal greenhouse gas and corporate average fuel economy (CAFE) standards.
- For every new vehicle, the test results are used to determine real world fuel economy and CO2 emissions. These adjusted results are used on the Fuel Economy and Environment Labels and on Fueleconomy.gov.
- How can I find and compare carbon dioxide (CO2) emission rates for specific vehicle models?
- Visit Fueleconomy.gov and click on “Find a Car.” Select your vehicle of interest. From the vehicle search results page, click on the “Energy and Environment” tab. A vehicle’s GHG emissions rate (g/mile) and GHG rating (1-10 scale) can be found on that search results page.
- When shopping at a dealership, check out tailpipe CO2 emission rates on vehicle Fuel Economy and Environment Labels. The labels also feature a 1-to 10 Fuel Economy and GHG rating to enable easy comparison shopping.