In many states, automobiles must pass a smog test to be legally driven on public roads. You can talk with a professional, like West Coast Smog, to learn more about this test. As with any test, there are ways to prepare for this one. Here are two things you can do to increase your vehicle's chances of passing an emissions test.

Take the Highway on Your Way to the Testing Site

Whether your vehicle passes or fails the smog test will depend largely on how well your automobile's catalytic converters perform. Catalytic converters reduce the amount of harmful emissions put off by automobiles -- the exact type of emissions that the test is checking for.

As Science Daily explains, catalytic converters don't work well at low temperatures. The metal particles in them only work efficiently once a minimum temperature is reached. Until your engine heats up to at least this temperature, the catalytic converter won't work properly. Residues from gas and oil can build up in them at lower temperatures, and these residues can create harmful pollutants that the test will find.

To ensure there isn't gas or oil residue in your vehicle's catalytic converter, drive your automobile on the highway before taking it in for an smog test. Going several miles down a freeway will make your engine work harder, which will increase its temperature. Once your engine is fully warmed up, the particles in your automobile's catalytic converter will begin burning off any excess residues. It will be ready for the smog test.

Check Your Tire Pressure

When you pull into the garage that will be performing the smog test, check your vehicle's tire pressure before letting a mechanic take it into a service bay. If the tires are flat, inflate them to the proper pressure. (You can find the correct tire pressure for your vehicle in the owner's manual.)

A lot of states' smog tests include a dynamometer test. During this part of the smog test, the vehicle is put on rollers. The rollers let the tires spin at high speeds without actually making the vehicle move. While the tires are turning, the amount of exhaust produced is measured.

If your tires are underinflated, your engine will need to work harder to bring the tires up to the minimum required rotations per minute. This will increase how much exhaust is produced. Keeping your tires inflated will ensure your engine can work as efficiently as possible during this portion of the smog test, thus producing fewer emissions.

Treat your vehicle's smog test like you would any other exam. Prepare for it. Take it on the highway and check the tire pressure before getting it tested, so it has the best chance of passing the test.