With gas prices on the rise, drivers are looking for just about any way they can improve their vehicle's fuel economy. Although there are many high-MPG cars on the market right now, not everyone can afford to buy a new car outright. Fortunately, there are some quick repairs and replacements drivers can perform on their cars to help with fuel economy.

For many years, replacing the air filter on a vehicle was a quick, easy and affordable way to do this. Those who are only vaguely familiar with their engine might be wondering what air has to do with fuel. Engines run on a mixture of gasoline and oxygen, which is then combusted in the cylinders of the engine to propel the car forward. The air filter's job is to let oxygen through while preventing any nasty particles or contaminants from getting into the engine.

In an older vehicle with a carbureted engine, the air filter was much more important when it came to fuel economy. Carburetors were used through the 1980s, at which point the auto industry switched to electronic fuel injection on almost all vehicles. The carburetor's job is to mix the air and fuel together before delivering it to the engine. Clogged air filters that blocked air would thus result in an imbalance, and the car would need to use more fuel, killing the fuel economy.

Electronic fuel injection has changed all that, however. Now, as long as the oxygen sensor is functioning correctly, the vehicle can keep the right mixture of fuel and oxygen even if the air filter is clogged. This means replacing an air filter on a modern car will not directly impact MPGs. That being said, it does have a big effect on performance. Drivers who replace a clogged air filter will improve the acceleration time of their vehicle significantly. Thus, it can still have an effect on fuel efficiency - if the driver is using the gas pedal more because he or she is not getting the desired performance, the car is likely burning through fuel more quickly.

Fortunately, replacing the air filter is one of the easiest auto maintenance fixes, and even amateur mechanics should be able to pull it off with no problem. The first step is locating the air filter. This can easily be found using the owner's manual, but if the driver doesn't have one, it should be simple to spot. The air filter is typically housed in square or rectangular casing, and will be located somewhere between the engine and grille.

Opening the casing may require unscrewing several screws, or possibly using a flathead screwdriver in order to pry off clips keeping the housing in place. Hold the air filter up to a light to check if it needs replacing. The general rule is that if light is getting through, air is getting through.

If the air filter does need replacing, it's fine to drive to the auto parts store with the filter removed. Oxygen will still get to the engine in this case. Some minor particles will find their way through as well, but this is fine in small doses - just don't make a habit of driving around with no filter.

Completing this repair is as simple as buying a compatible replacement for your filter and placing it where the old one used to be. If you have the old filter, you can likely find an exact replacement. Install the new filter and you should notice a nice performance boost - and maybe you'll hit the gas station less often as well.