A Consumer Guide to Auto Emission Inspection
and Maintenance (I/M) Programs

A car is a major investment, second only to buying a house, for most people. Part of the cost of a modern car is its pollution control system -- the catalytic converter and other equipment that removes smog-forming pollution from the tailpipe. Maintaining your car will help you protect your investment, help your car run better, improve your gas mileage -- and also help fight smog. Automobile emission inspection tests are important because it is very hard for the driver to tell when there is a problem with the pollution control system. Modern emissions testing, combined with required auto repair programs, is so effective that these measures are required in all states with serious smog problems. States have plenty of flexibility to design an inspection and repair program that fits their needs. Auto Inspection and Maintenance (I/M) programs are designed to make sure that the cars we buy and drive perform their best -- and live up to their pollution control promise. That protects the consumer. And it makes the air cleaner for all of us.

Why Should I Worry About Air Pollution?
Polluted air can shorten your life and make you sick. It can cause coughing, chest pains and shortness of breath. Some chemicals found in polluted air cause cancer, birth defects, nerve damage and long-term injury to lungs and breathing passages. Air pollution also damages the environment.

What Causes Air Pollution?
Air pollution comes from factories, businesses, consumer products, and, most of all, from cars, trucks and buses. Pollution from vehicles cause two of our worst air pollution problems, smog and carbon monoxide. Ozone, or smog, irritates the lungs, eyes and other tissues. It can cause or worsen respiratory problems. Smog can be a serious problem for anyone whose lungs are working hard -- children, the elderly, those with lung disease and even healthy adults exercising outdoors during a smog episode. Carbon monoxide interferes with the blood's ability to carry oxygen to the brain. CO can slow reflexes and affect thinking skills. Pregnant women and people with heart or lung disease are particularly at risk. In high concentrations, carbon monoxide kills.

But Aren't Today's Cars Clean?
Cars are much less polluting today than they were in the 1960's. But there are more cars on the road today, and we drive more. More than 195 million cars and trucks are on the road, averaging more than two per family. We drive an astounding 6.3 billion miles every single day, compared to 2.4 billion in 1965. Today's urban sprawl means more driving (VMT's) making smog a regional problem. Most of the worst smog readings occur in the suburbs and even in state and national parks away from our cities.

What is I/M?
Auto inspection and maintenance (I/M) programs require the testing of motor vehicles in parts of the country with unhealthy air and the repair of those that do not meet standards. I/M tests use special equipment to measure the pollution in your car's exhaust. These tests check that your car's key emission controls are installed as designed and then analyze the exhaust to check acceptable control of carbon monoxide and hydrocarbons (which form smog). Advanced tests also check nitrogen oxide emissions (which also form smog). Standards are set according to your car's model year. If your car exceeds those limits, it usually will pass its retest after minor adjustments, maintenance and repairs.

Why Do We Need Auto Emission Testing?
Cars don't always perform well on the road as they do in prototype tests. Smog inspections let motorists know when pollution control devices are malfunctioning and when fuel is being wasted. Repair programs make sure every car is doing its share of the cleanup job.

Does I/M Work?
I/M programs have been able to reduce air pollution by up to 30% in some states. In most communities, I/M is the best smog fighting tool available, and one of the cheapest. In fact, the smoggiest cities won't achieve clean air without I/M.

Must Every State Have the Same I/M Program?
States have the flexibility to develop their own I/M programs based on local conditions, as long as the states stay on their air pollution cleanup schedule. Generally speaking, the most technically advanced I/M testing and repair programs yield the greatest clean air benefits.

Why Does Every Car Have To Be Tested?
Any car that has malfunctioning emission controls or is poorly maintained may be polluting the air. (And it's costing you money.) On average, cars on the road emit three to four times more pollution than standards allow for new cars. Finding and fixing the high emitting vehicles can yield dramatic clean air benefits.

What About Industry's Role in Clean Air?
In partnership with the U.S. Environmental Protection Agency, businesses and industry are reducing their emissions. But it is not enough. We need to make our vehicles less polluting, too. The goal is to make sure all Americans have air that is fit to breathe. The federal Clean Air Act -- the nation's blueprint for cleaning up air pollution -- also continues to require ever cleaner new cars, trucks and buses. But that's not enough. Cars must not only be clean when we buy them; they must stay clean during their useful life to reduce pollution. And that's where you come in.

Are There Other Ways to Identify Polluting Cars?
Remote sensing devices placed on the side of roads can identify some polluters, but are no substitute for I/M. Cars passing by are checked for pollution from the exhaust system as the vehicle moves down the road. The accuracy of these checks is limited. They won't evaluate every vehicle and they won't catch such serious problems as emission leaks under the hood, where a great deal of pollution occurs.

Aren't the Clunkers Really To Blame for Smog?
Not necessarily. A well maintained 10-year-old car can be cleaner than a poorly maintained 5-year-old car. I/M programs recognize that pollution control systems do "age." In most states, older vehicles will not have to pass as stringent a test as newer vehicles. In California, cars are tested to the standard for the year they were manufactured.

Is I/M a Hassle?
I/M is worth the effort. The test takes only a few minutes. Even where tests are done at central locations, lines tend to be short except on a few of the busiest hours every month. For a shorter wait, avoid the busiest times, usually at the beginning and end of the month.

Besides Clean Air, What's In It For Me?
Smog inspections help consumers protect their investment in several ways. When pollution controls malfunction under warranty the auto maker must pay for repairs. (Warranty coverage changed beginning with 1995 cars, so be sure to check your owner's manual.) A well-tuned car will run more efficiently, saving gas. If your car fails an I/M test and you have it repaired, your gasoline cost could fall by six to 13 percent. In many cases, fuel savings will completely offset the repair costs. And your car will run better and longer. Some pollution repairs also will improve vehicle safety, since some of the faulty equipment responsible for excess pollution also can cause such hazardous conditions as stalling and surging. Clean air benefits are substantial. Economists estimate unhealthy air costs billions of dollars every year in health care and lost work time. And the benefits go far beyond dollars and cents especially for sick children, the elderly and others at risk from smog.