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 much tailpipe carbon dioxide (CO₂) is emitted from driving one mile?
  • The average passenger vehicle emits about 404 grams of CO₂ per mile

• What are the average annual carbon dioxide (CO₂) emissions of a typical passenger vehicle?
  • A typical passenger vehicle emits about 4.6 metric tons of carbon dioxide per year.
  • This assumes the average gasoline vehicle on the road today has a fuel economy of about 22.0 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 produce methane (CH₄) and nitrous oxide (N₂O)  from the tailpipe and hydrofluorocarbon emissions from leaking air conditioners. The emissions of these gases 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.

• What are the tailpipe emissions from a plug-in hybrid electric vehicle (PHEV) or an electric vehicle (EV)? What about hydrogen fuel cell vehicles?
  • A vehicle that operates exclusively on electricity (an EV) will not emit any tailpipe emissions. A fuel cell vehicle operating on hydrogen will emit only water vapor.
  • Calculating tailpipe emissions for PHEVs is more complicated. PHEVs can operate on electricity only, gasoline only, or some combination of electricity and gasoline. A PHEV operating on electricity only (like an EV) does not generate any tailpipe emissions. When a PHEV is operating on gasoline only, it creates tailpipe emissions based on the PHEV’s gasoline fuel economy. Tailpipe emissions for a PHEV operating on both electricity and gasoline cannot be calculated without detailed information about how the PHEV operates. The overall tailpipe emissions for a PHEV can vary significantly based on the PHEV’s battery capacity, how it is driven, and how often it is charged. 

• Are there any greenhouse gas emissions associated with the use of my vehicle other than what comes out of the tailpipe?
  • Driving most vehicles creates tailpipe greenhouse gas emissions. Producing and distributing the fuel used to power your vehicle also creates greenhouse gases. Gasoline, for example, 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 greenhouse gas emissions.
  • 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 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 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. 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 CO₂ emission rates for specific vehicle models?
  • Visit Fueleconomy.gov and click on “Find a Car.” From the vehicle search results page, click on the “Energy and Environment” tab. A vehicle’s greenhouse gas emissions rate (g/mile) and GHG rating can be found there.
  • 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 Greenhouse Gas Rating to enable easy comparison shopping.

• Where can I find information on the emissions of the transportation sector as a whole?
  • You can find documents on greenhouse gas emissions on Carbon Pollution from Transportation.
  • EPA also publishes industry-wide data in the report, “Light-Duty Automotive Technology, Carbon Dioxide Emissions, and Fuel Economy Trends.” This report analyzes trends in fuel economy and CO₂ emissions for new light duty vehicles from 1975 to the present.

Other useful sources include:

• Fueleconomy.gov
• U.S. Greenhouse Gas Inventory Report
• Greenhouse Gas Equivalencies Calculator
• Household Carbon Footprint Calculator