How Air Filters Improve Your Car’s Fuel Efficiency

How Air Filters Improve Your Car’s Fuel Efficiency

Written by May 10, 2023

There are many parts of your car, both moving and otherwise, that play a vital role in its day-to-day operation. Some, however, remain a bit obscure, at least when stacked up against the obvious contenders like tires, the engine or oil.

For instance, air filters play an essential role in maintaining the efficiency and performance of a car's engine, but they’re often last on the maintenance list, and that’s a problem. Air filters are capable of improving your car’s fuel efficiency - albeit indirectly - which means less money saved at the pump. How, you might ask? Read on to learn more.


Air filters ensure that the continuous rush of air entering the engine is clean and free from dust, debris, and other contaminants. Therefore, a clean air filter allows for smooth and unrestricted airflow, which is a vital part of the combustion process. When the engine receives a sufficient amount of clean air, it can burn fuel more efficiently, resulting in improved fuel economy. The dirtier the air, the less optimized this airflow becomes, which leads to a decrease in fuel efficiency.


Your car’s engine relies on a precisely balanced mixture of fuel and air to facilitate proper combustion. If your car’s air filter is dirty or clogged, airflow becomes restricted, which leads to a “rich” fuel mixture of more fuel, and less air. This kind of mixture can decrease fuel efficiency and cause incomplete combustion, resulting in increased emissions. A clean air filter ensures that the right amount of air reaches the engine, maintaining the optimal fuel-to-air ratio at all times. As you can already tell, your car’s air filter is far more important than you might have thought!


Obviously, a dirty air filter will allow contaminants to pass through and enter the engine, which can lead to potential problems down the road. Increased wear and tear of critical components like cylinders, piston rings, and valves will compound over time, leading to reduced engine performance and decreased fuel efficiency. By keeping the air clean, the air filter helps prevent premature wear and tear of these vital components, ensuring that the engine operates as the manufacturer intended, while maintaining efficiency over time. Think of it as a shield that protects the vital parts of the engine from premature wear, which will save money not only on gas, but engine maintenance as well. It’s not uncommon to see clogged air filters deposit dirt and rust into the engine’s combustion chamber, which can damage the crankshaft and bearings, leading to thousands of dollars in costly repairs.


Many of today’s cars come equipped with a device known as a mass airflow sensor (MAF), which measures the amount of air entering the engine at any given time. If your air filter is dirty or clogged, it may deposit particles on the MAF sensor, which will affect its accuracy, causing incorrect readings. This can lead to an improper fuel-to-air ratio, and negatively impact fuel efficiency as a result. Clean air filters help maintain the MAF sensor's accuracy, allowing the engine control unit (ECU) to make precise fuel adjustments for better efficiency. Gone are the days of completely analogue vehicles, and digital instruments like the MAF and ECU are now inseparable from the fuel efficiency equation. Make sure to keep your air filter in tip top shape so you can be sure these two devices are registering correctly at all times.


It's important to regularly inspect and replace your air filter according to the manufacturer's recommendations, which will ensure that the engine receives a consistent supply of clean air, thereby promoting optimal fuel efficiency and performance. If you aren’t sure how often you should clean your air filter, then stick to the general rule of thumb - 2 years, or 48,000km. This will fluctuate based on your specific driving conditions and environment, so be sure to ask a professional. Typically, it’s good practice to have your air filter inspected when you take your car in for an oil change, just to be safe. Most air filters are inexpensive, especially when weighed against costly damages.


Air filters may look simple and mundane, but their presence is vital to maintaining the stability and reliability of your vehicle, while cutting down on your fuel costs at the same time. Every penny saved is a penny earned, and there’s no sense paying more at the pump than you have to, especially given today’s exorbitantly high prices. The process of replacing a dirty air filter is both simple and cheap, so make sure to add it to your maintenance list!

If you’re in the market for a quality pre-owned vehicle backed by a rigorous 150 point inspection process, and yes, brand new air filters, then DriveAxis stands ready to help! You’re sure to find the most desirable vehicle from our inventory, and you’ll feel safe driving it off the lot, and for years to come. Worried about financing? Don’t be - we handle it all in-house in order to guarantee approval, regardless of your credit history! Contact us today to learn more!

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