What is the average CO2 emission by a car?
Globally, new passenger cars on average emit roughly 120 grams of CO2 per kilometer in recent years, with pronounced regional differences: about 110–120 g/km in much of Europe, and roughly 220–250 g/km in the United States. These figures refer to tailpipe emissions from conventional gasoline and diesel engines and do not include manufacturing or end-of-life impacts.
Overview and what the figure means
CO2 emissions per kilometer (g/km) is the standard metric used to compare how much climate pollution a car produces while driving. It focuses on tailpipe emissions from combustion and is influenced by vehicle type, efficiency, and how the car is used. Different regions publish slightly different benchmarks due to fleet composition, fuel standards, and adoption of electrified vehicles. When discussing “average car emissions,” it helps to specify whether you’re talking about new vehicles, tailpipe emissions, and whether lifecycle factors are included.
Regional snapshots
These figures reflect typical tailpipe emissions for new passenger cars and illustrate how averages vary around the world.
- Europe: roughly 105–120 g/km in recent years, with many countries pushing averages toward the lower end of that range through tighter standards and higher electrification.
- United States: approximately 220–250 g/km, reflecting heavier fleets and a slower transition to electrification in some segments.
- China and other major markets in Asia-Pacific: generally in the 150–180 g/km range, depending on the mix of traditional gasoline/diesel cars, hybrids, and growing EV share.
- Other regions: highly variable, from well under 100 g/km in markets with high EV uptake to well above 200 g/km in areas with older fleets and limited efficiency gains.
Note: These numbers refer to tailpipe CO2 from typical new passenger cars and exclude lifecycle emissions from manufacturing, battery production, and end-of-life processing. They are intended to illustrate relative differences rather than pin down a single universal value.
What drives the differences in average emissions?
Several factors determine how much CO2 a car emits per kilometer, and those factors help explain regional differences in the numbers above.
- Vehicle weight and size: larger, heavier cars require more fuel to move, raising CO2 per kilometer.
- Engine efficiency and technology: advances in engines, transmissions, and downsizing with turbocharging can lower CO2 per kilometer for a given performance level.
- Share of electrified vehicles: hybrids, plug-in hybrids, and especially full electric vehicles reduce tailpipe CO2 intensity, depending on how electricity is produced.
- Fuel type and quality: gasoline vs. diesel vs. alternative fuels; efficiency standards influence emissions.
- Driving patterns and usage: urban stop-and-go driving tends to increase per-kilometer emissions relative to highway cruising, though modern engines run more efficiently at steady speeds.
- Policy and standards: regional emissions targets, fuel economy regulations, and incentives shape the pace of fleet modernization.
- Lifecycle considerations (beyond tailpipe): manufacturing, battery production, and end-of-life processing add to the total climate impact, with EVs often showing higher upfront manufacturing emissions but lower lifetime emissions if powered by clean electricity.
Understanding these drivers helps explain why an “average car” value is not a single number and why policymakers and researchers emphasize both fleet turnover and clean energy generation when reducing overall CO2 footprints.
Lifecycle considerations
Beyond tailpipe emissions, lifecycle assessments account for manufacturing, battery production, vehicle use, and end-of-life handling. For many cars, manufacturing and battery-related emissions are a larger share of life-cycle CO2 for electric vehicles than for conventional cars, but this is offset over time by the lower emissions from electricity used during operation in low-carbon grids. The balance depends on battery size, vehicle efficiency, and how electricity is generated where the car is charged.
Summary
The average CO2 emission of a car depends on where you are and what type of car you consider. For new passenger cars, tailpipe emissions typically fall around 110–120 g/km in Europe, about 220–250 g/km in the United States, and 150–180 g/km in many parts of Asia-Pacific, with wide variation elsewhere. Electrification and cleaner energy sources are gradually lowering these numbers, especially in fleets that include more hybrids and electric vehicles. When evaluating a car’s climate impact, it helps to distinguish tailpipe emissions from lifecycle emissions, which can tell a different part of the story as production and electricity mix change over time.
