Car Pollution: How Vehicle Emissions Affect Health and the Environment
Learn how pollution from cars, trucks and buses impacts health and the environment.
Last updated: August 25, 2026
Gasoline and diesel vehicles produce two different but connected pollution problems: heat-trapping carbon dioxide and unhealthy air pollution. Their emissions include nitrogen oxides, volatile organic compounds, carbon monoxide, fine particles and toxic chemicals. Cars also create particle pollution through tire, brake and road wear.
Carbon dioxide does not usually irritate your lungs the way smoke or smog can, but it builds up in the atmosphere and traps heat.
Tailpipe air pollutants, on the other hand, can directly affect the air in neighborhoods, near roads, around schools, and inside communities already overburdened by pollution.
The good news is that cleaner vehicles, better transportation choices, and helping high-gasoline drivers switch to electric vehicles can quickly cut pollution. Read more below.
Car Pollution At a Glance
- A typical gasoline passenger vehicle emits about 4.6 metric tons of tailpipe carbon dioxide per year, based on the driving and fuel-economy assumptions used by the U.S. Environmental Protection Agency.
- Burning one gallon of gasoline produces approximately 8,887 grams, or 19.6 pounds, of carbon dioxide.
- Cars and vans produced about 3.8 gigatons of CO2 in 2023 and accounted for more than 10% of global energy-related CO2 emissions, according to the International Energy Agency.
- Mobile sources, including cars, trucks and other transportation equipment, produced approximately 45% of U.S. nitrogen oxide emissions in the 2020 National Emissions Inventory.
What is Car Pollution?
Car pollution is the mixture of greenhouse gases, smog-forming gases, toxic chemicals and particles produced by vehicles and the fuels that power them. Gasoline and diesel vehicles emit pollution when fuel is produced, transported and burned. Vehicles also create some pollution as tires and brakes wear.
It helps to separate vehicle pollution into two related problems:
- Climate pollution: Carbon dioxide (CO2) is the main greenhouse gas released by gasoline and diesel vehicles. It accumulates in the atmosphere and contributes to climate change.
- Air pollution: Vehicle exhaust and wear produce nitrogen oxides (NOx), volatile organic compounds (VOCs, carbon monoxide, particulate matter and toxic air pollutants. Some are harmful when inhaled; others react in the atmosphere to form ground-level ozone or additional particles.
How Do Cars Pollute the Environment?
Cars and trucks create pollution in several ways:
- Tailpipe emissions: An engine burns gasoline or diesel and releases CO2 along with NOx, carbon monoxide, VOCs, particulate matter and toxic pollutants. The exact mixture depends on the fuel, engine, emissions controls, operating temperature and driving conditions.
- Evaporative emissions: Gasoline can evaporate from a vehicle's fuel system even when the engine is not running. These vapors contain hydrocarbons that contribute to ground-level ozone.
- Fuel production and distribution: Extracting oil, refining it into fuel and transporting the fuel require energy and can release greenhouse gases and air pollutants before a driver buys a gallon.
- Brake, tire and road wear: Vehicles produce particles as tires and road surfaces wear. Braking also produces particles, although regenerative braking can reduce brake wear in electric and hybrid vehicles. Vehicle weight, tire design, driving style and road conditions all affect these non-tailpipe emissions.
- Vehicle manufacturing: Producing any vehicle requires raw materials and energy. These emissions are part of a vehicle's life-cycle footprint rather than its on-road tailpipe emissions.
How Does Vehicle Pollution Affect Health?
Traffic-related air pollution is associated particularily with harm to the lungs and heart. Fine particles, nitrogen dioxide, ozone, carbon monoxide and toxic compounds affect the body in different ways, and people are generally exposed to a mixture rather than one pollutant at a time.
The EPA reports that more than 45 million people in the United States live within 300 feet of a major transportation facility. Research has shown that exposure to motor-vehicle pollution can cause lung and heart problems and premature death.
Nitrogen oxides and ground-level ozone
Nitrogen oxides help form ground-level ozone and particulate matter. Ozone can irritate airways, worsen asthma and make it harder to breathe. Nitrogen dioxide exposure is associated with respiratory effects, particularly for children, older adults and people with asthma. Learn more from the EPA's nitrogen dioxide health information.
Particulate matter
Fine particles can travel deep into the lungs, and some can enter the bloodstream. Particle pollution is associated with cardiovascular and respiratory effects and premature death. Vehicles contribute particles directly through exhaust and wear and indirectly through gases that form particles in the atmosphere.
Carbon monoxide and toxic pollutants
Carbon monoxide interferes with the blood's ability to carry oxygen and can be especially dangerous in enclosed or poorly ventilated spaces. Vehicle-related air pollution can also include toxic compounds such as benzene and formaldehyde.
Unequal impact and exposure
Children, older adults, people with asthma or heart disease, outdoor workers and people who spend substantial time near heavy traffic can be especially vulnerable. Exposure is also unequal: highways, freight routes, ports and other high-traffic facilities have often been placed in or near communities already burdened by other sources of pollution.
As a pediatrician, I see firsthand the harm caused by our oil addiction. Children living in polluted areas experience higher rates of asthma and slowed lung development. This is a terrible burden we are putting on our children and future generations. We must dedicate all available resources to get off fossil fuels to protect children today and into the future.
What Do Cars Release Into the Air?
Pollutant |
Where it comes from |
Why it matters |
|---|---|---|
| Carbon dioxide (CO2) | Burning gasoline and diesel; fuel production | The primary climate pollutant from conventional vehicles |
| Nitrogen oxides (NOx) | High-temperature combustion in engines | Contribute to ground-level ozone and particle pollution; can worsen respiratory problems |
| Volatile organic compounds (VOCs) | Tailpipe exhaust and evaporating fuel | React with NOx in sunlight to form ground-level ozone; some VOCs are toxic |
| Particulate matter (PM2.5 and PM10) | Exhaust, especially diesel exhaust; brake and tire wear; road dust; atmospheric reactions | Fine particles can enter deep into the lungs, and some can reach the bloodstream |
| Carbon monoxide (CO) | Incomplete fuel combustion | Reduces the blood's ability to carry oxygen and can be especially dangerous at high concentrations |
| Air toxics | Fuel and exhaust emissions | Compounds such as benzene and formaldehyde are associated with serious health risks |
Some vehicle pollutants are emitted directly. Others form after emissions enter the air. For example, NOx and VOCs react in sunlight to form ground-level ozone, a principal component of smog. Nitrogen oxides can also contribute to the formation of fine particles. The EPA notes that PM2.5 is small enough to penetrate deep into the lungs and, in some cases, enter the bloodstream.
Are Cars The Biggest Polluters?
Cars are not the biggest source of every kind of pollution, but they are one of the biggest sources of pollution from transportation and a major contributor to climate pollution.
- In the United States, transportation produced about 1,848 million metric tons of energy-related carbon dioxide in 2024, compared with 4,772 million metric tons across all U.S. energy sectors. That means transportation was responsible for roughly 39% of U.S. energy-related CO2 emissions.
- Cars, SUVs, and small trucks are especially important because they use most of the gasoline sold in the United States. The U.S. Energy Information Administration says light-duty vehicles — including cars, SUVs, and small trucks — account for about 91% of U.S. gasoline consumption.
- Globally, road transport is also a major source of carbon pollution. The International Energy Agency reports that road transport produced just over 6 gigatons of CO2 in 2024, and that passenger cars and vans made up more than 60% of road transport CO2 emissions.
What Percentage of Pollution is Caused by Cars?
There is no universal percentage because “pollution” can refer to different substances, sources, geographies and years. However, the figures below answer several related questions without mixing their denominators.
| Geography and data year | Vehicle/source category | Pollutant measured | Best concise answer | What the percentage is compared with |
|---|---|---|---|---|
| Global, 2023 | Passenger cars and vans | CO2 | More than 10% | Global energy-related CO2 emissions; IEA |
| Global, 2024 | Passenger cars and vans | CO2 | More than 60% | Road-transport CO2 emissions; IEA |
| United States, 2024 | All transportation | Energy-related CO2 | About 39% | Total U.S. energy-related CO2 emissions, calculated from U.S. EIA sector totals |
| United States, EPA inventory basis | All transportation | All greenhouse gases, measured as CO2-equivalent | About 28% | Total U.S. greenhouse gas emissions; EPA |
| United States, EPA national inventory | Mobile sources, including highway and non-road sources | Nitrogen oxides | About 45% | Total U.S. nitrogen oxide emissions; EPA |
For a sense of scale, the US consumes over one third of the world’s gasoline – more than three times that of the next biggest gasoline user, China:
In 2024, approximately 137.84 billion gallons of gasoline were consumed in the U.S. (an average of about 377 million gallons every day). To put that into perspective, that’s enough gasoline to fill a Ford Explorer’s tank roughly 7.7 billion times in a single year.
According to the U.S. Energy Information Administration’s 2024 energy-related CO₂ data, the U.S. transportation sector emitted approximately 1,848 million metric tons of CO₂ in 2024, representing about 39% of total U.S. energy-related CO₂ emissions.
Learn more about gasoline consumption in the United States and get the facts about gas.
How Much Pollution Does One Car Produce?
The amount varies with fuel economy, annual mileage, fuel type, vehicle condition, temperature, congestion and driving behavior. The EPA estimates that a typical gasoline passenger vehicle emits about 4.6 metric tons of tailpipe CO2 each year. Its estimate assumes approximately 11,500 miles of annual driving and fuel economy of about 22.2 miles per gallon.
Gasoline Superusers, defined as U.S. drivers in the top 10% for gasoline consumption, use at least 1,100 gallons of gasoline a year. Gasoline Superusers add at least 11 tons of carbon dioxide to the atmosphere each year.
The EPA also estimates that the typical vehicle produces about 400 grams of CO2 per mile. A more personalized estimate can be made from a vehicle's gasoline use because every gallon burned produces approximately 8,887 grams, or 19.6 pounds, of tailpipe CO2.
Tailpipe Emissions Visualizer
The Tailpipe Emissions Visualizer is grounded in research from the U.S. Department of Energy, which estimates that burning just one gallon of gasoline emits approximately 20 pounds of carbon dioxide (CO₂) into the atmosphere. Electric vehicles have 0 tailpipe emissions - no matter how many miles you drive them.
What Causes High CO2 Emissions in Cars?
A gasoline or diesel car's carbon dioxide emissions are driven primarily by how much fuel it burns. Because every gallon contains a known amount of carbon, more gallons burned generally means more carbon dioxide released.
The largest factors are:
- Vehicle size and weight: Moving a larger, heavier vehicle usually requires more energy.
- Fuel economy: A low-MPG vehicle burns more fuel to travel the same distance.
- Miles driven: A relatively efficient car can still produce substantial annual emissions if it is driven very long distances.
- Congestion and idling: Fuel can be consumed while a vehicle travels slowly or not at all.
- Speed and acceleration: Aggressive acceleration and inefficient speeds can increase fuel consumption.
- Temperature, terrain and accessory use: Cold weather, steep grades, heating and air conditioning can affect efficiency.
- Maintenance and tire pressure: Poor maintenance and underinflated tires can reduce fuel economy.
For example, burning 500 gallons of gasoline produces approximately 9,800 pounds of tailpipe CO2. That means replacing a low-efficiency vehicle driven many miles can avoid substantially more fuel use than replacing a lightly driven, efficient vehicle.
How Can We Reduce Vehicle Pollution?
To reduce carbon dioxide pollution and air pollution from vehicles, we need to reduce how much gasoline and diesel we use. For people who use a lot of gasoline, switching to an electric vehicle can be very effective in both reducing vehicle pollution and saving money.
Learn about 10 ways to reduce air pollution in our nonprofit's free guide.
EVs are Cleaner than Gas-Powered Cars
Electricity is getting cleaner every year, as more of it comes from clean, renewable sources like sun and wind, and 24/7 power from renewables plus battery storage is becoming cheaper than fossil fuels.
In all 50 states, according to the U.S. Department of Energy, the annual emissions from an electric vehicle are less than those of a gas car. Across the lifetime of the vehicle, total emissions depend on how much the vehicle is driven.
For a gas car, the day it leaves the dealership lot is its cleanest day; for an EV, the day it leaves the dealership is its dirtiest day. If the EV is never driven, over its lifetime it will have more total emissions than a gas car, because (currently!) more emissions are involved in the manufacture of an EV and its battery than for a gas car.
The more the vehicles are driven, the faster the EV becomes cleaner than the gas car. The typical “crossover” point for EVs is 15,000 to 20,000 miles.
The cleaner the power grid gets, the cleaner EVs get. A gasoline car keeps burning gasoline for as long as it is on the road. An EV can get cleaner over time as more electricity comes from lower-carbon sources.
Learn about the life cycle harms of gasoline.
In model year 2023, the highest-rated EPA combined fuel economy for gasoline vehicles was about 60 miles per gallon (MPG), while EVs achieved up to 140 mpg-equivalent (MPGe). (MPGe is an EPA measure of EV fuel economy in a common unit with gas-powered vehicles, where 33.7 kilowatt-hours of electricity are equal to the energy contained in one gallon of gasoline.)
Overall, fossil fuel vehicles make hundreds of times more waste than EVs. Claims to the contrary have been widely debunked. Indeed, in 95% of the world, EVs are cleaner.
Gasoline will always be a polluting fossil fuel that is burned once and gone forever. In contrast, there are reports of electric vehicle batteries lasting over 400,000 miles. New technology promises million-mile batteries. After the batteries can’t be used in vehicles, they have a second life providing battery electric storage for buildings. After that, their raw materials can be almost fully recycled, and recycling efforts are continuing to improve with government incentives.
How Switching To EVs Provide a Healthier, Cleaner Future
Unlike gas-powered vehicles, electric vehicles (EVs) produce zero tailpipe emissions, eliminating harmful tailpipe pollutants that degrade air quality and harm public health. Instead of burning fossil fuels, EVs require no exhaust system.
A widespread transition to EVs leads to:
- Significantly improved air quality
- Fewer pollution-related respiratory and cardiovascular illnesses
- Healthier cities and communities with cleaner, safer air
Switching to electric isn’t just an environmental decision - it’s a critical step toward protecting public health and reducing pollution-driven diseases.
Looking To Save Money On An EV in 2026?
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We can cut vehicle pollution faster by helping the biggest gasoline users switch to EVs
Prioritizing the drivers in the top 10% for gasoline consumption (“Gasoline Superusers”) for the switch to EVs will reduce vehicle emissions faster and more efficiently. As many Superusers are below the median income, this approach also save money for the lower-income households that are most burdened by gasoline expenditures.
In California, the average Superuser burns 3.5x more gasoline than the average non-Superuser: 1,260 gallons a year vs. 354 gallons for non-Superusers.
Switching all of California’s 5.4 million biggest gasoline users (roughly those in the top 20%) to EVs would cut gasoline use by 43%.
Cutting vehicle emissions by 50% would require 9 million EVs if the biggest gasoline users switched first, but 24 million EVs if the biggest gasoline users switched last.
Currently, EVs are being adopted by lower mileage drivers. The average EV driver only drives about 10,200 miles a year versus superusers who drive on average 24,000 miles a year.
Learn from our free webinar about how the gasoline superuser approach can help reduce car pollution faster and more equitably.
Conclusion
Car pollution is not just one problem. It is a climate problem, an air quality problem, a public health problem, and a household cost problem.
The numbers show why it matters. Transportation produces about 39% of U.S. energy-related CO2 emissions. Americans still burn more than 136 billion gallons of gasoline a year. Cars, SUVs, and small trucks account for most U.S. gasoline consumption. Globally, passenger cars and vans are responsible for most road transport CO2 emissions.
But those same numbers also point toward the solution. Reducing gasoline use — especially among the vehicles and drivers that burn the most — can cut pollution faster. Switching to electric vehicles, cleaning up electricity, reducing unnecessary driving, improving transportation options, and prioritizing communities most affected by pollution can all help build a cleaner, healthier future.
Pollution Ends Where Action Begins
Are you ready to join forces with thousands of others against vehicle pollution?
Stay informed with exclusive updates, expert insights and actions you can take from our award-winning nonprofit’s monthly Beyond Gasoline newsletter.
Gasoline is the biggest source of carbon emissions in the U.S.
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Every time I get behind a diesel truck, I'm smelling the exhaust, and I'm like, I don't want to add to that, I don't want to pollute. That's something that I felt just makes you feel good about it right? You buy an EV for all the mature, responsible adult reasons. And then you find out, like wow, this is way more fun to drive than my other vehicle. The acceleration was extremely surprising. Way more fun on a winding road. So that’s the cool cherry on top, where this is the most fun vehicle I’ve ever driven.
Average U.S. Gasoline Prices Have Been Far More Volatile Than eGallon Electricity Costs
Gas-powered vehicles do not just create pollution — they also tie drivers to a fuel market shaped by global shocks and oil volatility. This Coltura chart compares monthly average U.S. retail gasoline prices with an electricity eGallon price estimate. It helps connect those dots by showing how unstable gasoline prices have been compared with electricity.
Interested in a more updated and interactive version of the above chart? Check out Coltura's EV Cost Savings Index
Frequently Asked Questions About Car Pollution
Do Cars Release Carbon Dioxide?
Yes. Gasoline and diesel cars release carbon dioxide when they burn fuel. EPA estimates that one gallon of gasoline produces 8,887 grams of CO2, and that a typical passenger vehicle emits about 4.6 metric tons of CO2 per year.
What Gases Do Cars Emit?
Gasoline and diesel vehicles can emit carbon dioxide, carbon monoxide, nitrogen oxides, and volatile organic compounds. They can also emit toxic pollutants such as benzene and formaldehyde.
What Pollutants Do Cars Emit?
Cars emit climate pollutants and air pollutants. Carbon dioxide is the main climate pollutant from gasoline vehicles. Air pollutants from vehicles can include nitrogen oxides, volatile organic compounds, particulate matter, carbon monoxide, and mobile-source air toxics.
What Do Cars Release Into The Air?
Cars release carbon dioxide and other pollutants into the air when they burn gasoline or diesel. Carbon dioxide contributes to climate change, while pollutants such as nitrogen oxides, VOCs, fine particles, and toxic compounds contribute to unhealthy air.
How Do Cars Cause Air Pollution?
Cars cause air pollution by burning fuel in an engine. Exhaust leaves the tailpipe and adds pollutants to the air. Some pollutants, such as nitrogen oxides and VOCs, react in sunlight to form ground-level ozone, also known as smog.
How Do Cars Affect The Environment?
Cars affect the environment by producing carbon dioxide, using petroleum, contributing to smog and particle pollution, and increasing demand for oil extraction, refining, and transportation. The environmental impact depends on how much fuel a vehicle burns, how many miles it is driven, and how clean or dirty its fuel source is.
Are Cars Bad For The Environment?
Gasoline and diesel cars are bad for the environment compared with cleaner alternatives because they burn fossil fuels and emit carbon dioxide and air pollutants. Newer gasoline vehicles are generally cleaner than older gasoline vehicles, but they still produce CO2 whenever they burn fuel.
How Much Air Pollution Comes From Cars?
The answer depends on the pollutant. Transportation is a major source of nitrogen oxides, contributes to smog-forming pollution, and adds toxic pollutants and fine particles to the air. Pollution levels vary by location, vehicle type, traffic volume, fuel type, and local conditions.
What Percentage Of Carbon Emissions Come From Cars?
There is no single universal number. In the U.S., transportation produced about 39% of energy-related CO2 emissions in 2024. Light-duty vehicles account for most U.S. gasoline use, and passenger cars and vans produce more than 60% of global road transport CO2 emissions.
Do Cars Emit CO2 Even If They Are New?
Yes. New gasoline vehicles may be more efficient and cleaner than older gasoline vehicles, but they still release CO2 whenever they burn gasoline or diesel.
Do Electric Cars Have Tailpipe Emissions?
No. Battery electric vehicles do not have tailpipes and produce zero tailpipe emissions. Plug-in hybrid vehicles can still produce tailpipe emissions when they use gasoline.
Are Electric Cars Pollution-Free?
No vehicle is completely pollution-free. Manufacturing any vehicle creates emissions, and electricity generation can create pollution depending on the grid. However, electric vehicles have zero tailpipe emissions and usually have a smaller carbon footprint than gasoline vehicles over their lifetime.