Skip the auto shop - Our mechanics make house calls

Vehicle Emissions & Air Pollution

vehicle emissions and air pollution

Millions of Americans rely on vehicles to meet their transportation needs, but vehicles are a big contributor to air pollution. As more information is discovered on the effects of passenger vehicle pollution, technology is being developed to make cars and other vehicles more environmentally friendly. The potential health issues caused by air pollution can be very serious, so finding a way to prevent the causes of pollution is important.

In the past few years, efforts to develop environmentally friendly cars have increased, leading to clean vehicles and fuel technology that have the potential to reduce vehicle related air pollution. This technology includes vehicles that are fuel efficient and use less oil, and ones that use cleaner fuels, resulting in fewer emissions being produced. Electric cars have also been developed, and do not produce any tailpipe emissions.

In addition to new technology that can reduce air pollution, there have been strong state and federal policies put into place. Vehicle emissions standards have been developed and since 1998, have helped to reduce pollution from cars and trucks by approximately 90 percent. The US Environmental Protection Agency has developed vehicle emissions standards and states have further developed their own laws regarding vehicle emissions.

When vehicles undergo an inspection, they also undergo emissions testing. The amount of pollution emitted by a particular vehicle and the speed at which it consumes fuel depend on a variety of factors. The EPA has developed models that provide estimates for the average emissions of different types of automobiles. Emissions testing has been set up based on these estimates and cars must pass emissions testing, however there are some exemptions to testing. Drivers should familiarize themselves with the specific vehicle emissions laws for their state of residence to ensure they are in compliance. Mechanics often have the tools necessary to perform emissions testing.

EPA "Tier 3" Standards

The Environmental Protection Agency's Tier 3 standards refer to a set of standards that were adopted in 2014. The standards are set to be implemented in 2017, and are expected to immediately start to reduce air pollution caused by vehicle emissions. The Tier 3 standards will effect vehicle manufacturers, who will be required to improve emission control technology, as well as oil companies, who will be required to decrease the sulfur content of gasoline, resulting in a cleaner burn. When implemented, the Tier 3 standards will significantly reduce vehicle related air pollution and will also benefit public health.

Major Air Pollutants

There are many things that contribute to air pollution, but some of the major pollutants include the following:

  • Carbon Monoxide (CO) is a colorless, odorless gas that is poisonous and is formed during the fuel combustion process.
  • Hydrocarbons (HC) are pollutants that form ground level ozone in the presence of sunlight, when they react with nitrogen oxides. Ground level ozone is one of the primary ingredients of smog.
  • Particulate Matter includes particles of metals and soot, and are what give smog its color. Particulate matter is very fine, and can penetrate the lungs, posing a threat to human health.
  • Nitrogen Oxides (NOx) are pollutants that can cause lung irritation and can lead to respiratory infections.
  • Sulfur Dioxide (SO2) is a pollutant caused by burning fuels that contain sulfur. It can react when released into the atmosphere, causing the formation of fine particles.

Now that scientists know more about the effects of vehicle emissions on the environment, work continues to be done to develop technology that helps to reduce pollution. Laws and standards that have been put into place regarding vehicle emissions have already helped to reduce air pollution, and more continues to be done. For more information on vehicle emissions and air pollution, visit the following pages.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.


Post a question and get free advice from our certified mechanics.


More related articles

P0222 OBD-II Trouble Code: Throttle/Pedal Position Switch/Sensor B Circuit Low Input
P0222 code definition Throttle/Pedal Position Switch/Sensor B Circuit Low Input What the P0222 code means The manufacturer specifies a range of acceptable voltage to be produced from the throttle position...
How to Transfer a Car Title in Idaho
In order to prove ownership of a car, you must have the title. However, when a car is sold, given away or inherited, the title needs...
P2159 OBD-II Trouble Code: Vehicle Speed Sensor B Range/Performance
Diagnostic Trouble Code (DTC): P2159 P2159 code definition Vehicle Speed Sensor B Range/Performance Related Trouble Codes: P2158: Vehicle Speed Sensor B P2160: Vehicle Speed Sensor B Circuit Low P2161:...

Related questions

Q: Car making loud noise and barely running.

This sounds like it could be a serious problem for your car. My first recommendation would be to have this vehicle inspected by a certified mechanic as soon as possible to avoid these symptoms turning into larger problems. The list...

Q: How do i fix the timing on my car?

There are several ways to check and set the ignition timing. The most traditional method is to check timing with a timing light against the recommendations of Nissan for your 1990 240SX. However, there could be issues with timing due...

Q: Coolant temperature increase, service hybrid light on

Hello. If the coolant is getting hotter than normal it will also affect the hybrid system. If the coolant is low then this will occur. If the coolant level is fine then it is more than likely a weak water...