Keeping your engine healthy means routine maintenance, but one maintenance item is easy to forget. Your engine air filter is important to performance, efficiency, and even the reliability of your car. But with paper, gauze, and even foam engine air filters out there, how do you know which is best? That’s what we’re here to find out.

Paper vs Gauze vs Foam engine air filters

The three primary types of engine air filters are paper, gauze, and foam. Paper air filters are the most common and most affordable, offering impressive filtration at the expense of airflow and performance. Gauze air filters come in two types, oiled and dry. However, both offer improved airflow, performance, and efficiency over standard paper. However, there are some concerns over filtration capability, especially in dusty areas.

Finally, we have foam filters. Finding an exclusively foam air filter isn’t an easy task, however some aftermarket filters and intakes use a foam sleeve or guard. This adds a layer of particulate filtration without drastically inhibiting air flow.

Pros and cons of paper air filters

Paper air filters are the cheapest and most readily available option. And for most drivers, these are the most functional option. Because they offer the best filtration, they’re the best for keeping your engine healthy long term. Plus, you’ll save a ton over the more expensive gauze filters that claim better performance.

In truth, unless you’re pushing for every last horsepower, the paper air filter is an adequate, affordable solution. Modern technology means the airflow loss is negligible, and they offer much better particulate removal than a “high-performance” air filter.

Pros and cons of gauze air filters

That said, there are situations where a gauze air filter is the better option. For starters, if you want to improve the airflow of your entire intake system with an aftermarket unit, gauze filters are typically the only option. In this case, you’ll have a choice between oiled and dry gauze filters.

Oiled filters are impregnated with a synthetic oil solution that grabs dirt and hangs onto it. This enhances the filtration capability, though there are claims of that oil ending up on your valves and causing a buildup if the filter is over oiled. These filters don’t need to be replaced like paper filters, but they will require cleaning and re-oiling every 50,000 miles.

Meanwhile, dry filters avoid the oiling hassle white retaining improved airflow and adequate filtration. And while they don’t need to be re-oiled, they will need to be removed, cleaned, dried, and reinstalled every 50,000 miles.

Pros and cons of foam air filters

Adding a foam sleeve or cover over a gauze air filter can alleviate concerns about their filtration capabilities. These are often seen in aftermarket intake systems, like these from RacingLine, to reduce engine contamination while allowing for improved airflow and performance.

These are especially helpful in dusty areas, where the gauze filters are the least effective. This added bit of protection is worth it, but keep in mind that it does mean an additional cost every time the filter needs  cleaning.

Is aftermarket air filter worth it?

For 90% of the driving population, a clean paper air filter is more than adequate. Dropping a gauze air filter into a stock intake system won’t make for much performance gain, and the risk of dust and dirt entering your engine is significantly higher. And if you’re going to upgrade the entire intake, find a quality setup with a foam filter sleeve for the best possible protection.