Replacing the air filters in your 2020 Nissan Altima is one of the most important yet straightforward maintenance tasks you can perform to protect your vehicle's engine efficiency and cabin air quality. Your Altima utilizes two separate air filtration systems: an engine air filter that prevents harmful contaminants from entering your engine, and a cabin air filter that cleans the air entering your vehicle's interior. Regular replacement of both filters every 15,000-30,000 miles depending on driving conditions maintains optimal performance, fuel efficiency, and breathing environment for passengers. This comprehensive guide will walk you through both procedures with detailed, easy-to-follow instructions that can save you significant money on dealership service costs .

Understanding Your 2020 Nissan Altima's Air Filtration System

The 2020 Nissan Altima employs two distinct air filtration systems that serve different but equally important functions. The engine air filter protects your vehicle's heart by preventing abrasive contaminants like dust, sand, pollen, and debris from entering the combustion chambers. A clean engine air filter ensures the proper air-fuel mixture for optimal combustion, which directly impacts performance, fuel economy, and engine longevity. Meanwhile, the cabin air filter focuses on occupant comfort and health by cleaning the air that enters your vehicle's interior through the HVAC system. This filter traps pollutants, allergens, and airborne particles before they can circulate inside your cabin, creating a healthier environment for you and your passengers .

These two systems work independently but are equally crucial for maintaining your Altima's overall health and your driving comfort. While the engine air filter directly impacts mechanical performance, the cabin air filter affects your personal comfort and health during every journey. Both filters eventually become clogged with the particles they capture and require regular replacement to function properly. Understanding this distinction helps you appreciate why maintaining both systems is essential for your vehicle .

Neglecting either filter can lead to noticeable issues. A dirty engine air filter restricts airflow to the engine, potentially causing reduced power, decreased acceleration, lower fuel economy, and eventually triggering your check engine light. Similarly, a clogged cabin air filter results in reduced airflow through your vents, musty odors, increased interior dust, and impaired heating and cooling efficiency. In severe cases, a completely blocked cabin filter can even strain your blower motor, potentially leading to expensive repairs .

When to Replace Your 2020 Nissan Altima's Air Filters

Adhering to a regular replacement schedule for both air filters in your 2020 Nissan Altima is essential for preventive maintenance. For the engine air filter, Nissan recommends replacement approximately every 30,000 miles or 36 months under normal driving conditions. However, if you frequently drive in dusty, polluted, or sandy environments, or regularly encounter stop-and-go traffic with high particulate pollution, you should inspect and potentially replace the filter more frequently, perhaps every 15,000-20,000 miles .

The cabin air filter typically requires more frequent replacement—generally every 15,000 to 30,000 miles, or approximately once per year. Some experts suggest even more frequent replacement (every 12,000 miles or annually) if you have allergies or regularly drive in areas with high pollen counts or poor air quality. This increased replacement frequency is necessary because cabin filters not only capture dust and pollen but also absorb odors and trap microscopic particles that can affect respiratory health .

Beyond mileage-based schedules, watch for these warning signs that indicate your filters need attention:

​Signs your engine air filter needs replacement:​​

• Visible dirt, debris, or dark discoloration when visually inspected
• Decreased fuel economy
• Reduced engine performance and acceleration
• Unusual engine sounds or rough idling
• Illuminated check engine light (in some cases)

​Signs your cabin air filter needs replacement:​​

• Reduced airflow through HVAC vents even at higher fan speeds
• Musty or unpleasant odors when running the heating or air conditioning
• Increased dust accumulation on interior surfaces
• Excessive window fogging due to reduced HVAC efficiency
• Whistling sounds from the dashboard area

Performing a visual inspection is the most reliable way to determine if your filters need replacement. Even if you haven't reached the recommended mileage interval, environmental factors might necessitate earlier replacement. During oil changes or routine maintenance, take a moment to check both filters—this proactive approach can prevent more significant issues down the road .

How to Replace the Engine Air Filter in Your 2020 Nissan Altima

Replacing the engine air filter in your 2020 Nissan Altima is a straightforward process that requires no special tools and can be completed in about 10-15 minutes. The PR25DD 2.5L I4 engine found in most Altima models features an easily accessible air filter housing designed for simple maintenance .

Before beginning, ensure your vehicle is parked on a level surface with the engine cooled down. You'll need to purchase the correct replacement filter—compatible options include EcoGard XA11703, Purolator A31489, K&N 33-509, or Fram CA12551. Having a wet/dry vacuum handy can be helpful for cleaning the air box housing before installing the new filter .

​Step-by-Step Replacement Process:​​

1. ​Locate the air filter housing:​​ Open the hood and move to the driver's side of the engine bay. Identify the rectangular plastic air filter housing situated behind the headlight assembly. This housing has a large intake tube connected to it .

2. ​Open the housing clips:​​ The air box cover is secured by two silver metal latches on its front edge. Flip down both latches—first the left side, then the right. Once released, slide the cover forward slightly to disengage the two tabs on the rear edge from their corresponding slots .

3. ​Remove the old filter:​​ Lift open the air box cover to expose the old air filter. If you encounter resistance, double-check that all tabs and clips are fully released. Carefully slide the old filter out of the bottom housing section .

4. ​Clean the housing:​​ With the filter removed, inspect the bottom half of the air box for accumulated debris. Use a wet/dry vacuum to thoroughly clean out any dirt, leaves, or other contaminants. This ensures no debris enters your engine when the new filter is installed .

5. ​Install the new filter:​​ Place the new air filter into the bottom housing, noting that its specific shape allows installation in only one orientation—the correct way. The filter's rubber rim should face upward, and the wavy paper element should face downward toward the air intake direction .

6. ​Reassemble the housing:​​ Lower the cover back onto the housing, ensuring the rear tabs slide correctly into their slots. Press down firmly to ensure a proper seal, then flip both metal latches back into their locked positions. Verify that the housing is completely sealed with no gaps where unfiltered air could enter .

7. ​Final check:​​ Ensure all components are securely fastened, then start your engine and listen for any unusual sounds that might indicate an improper installation. Take a quick test drive to verify normal operation .

The entire process requires minimal mechanical experience and provides immediate benefits. Many Altima owners report noticing improved throttle response and smoother engine operation immediately after replacing a clogged engine air filter. This simple maintenance task directly contributes to your engine's longevity and efficient operation .

How to Replace the Cabin Air Filter in Your 2020 Nissan Altima

The cabin air filter in your 2020 Nissan Altima is located behind the glove compartment, making it slightly more involved to access than the engine air filter but still very manageable for a DIY enthusiast. Replacement typically takes 15-20 minutes and requires only basic tools—primarily a screwdriver for some model variations .

​Types of Cabin Air Filters:​​
Before beginning, you'll need to purchase a replacement filter. Several types are available:

• ​Standard pleated paper filters:​​ Basic filtration for dust and pollen at an affordable price point
• ​Activated carbon filters:​​ Enhanced filtration that captures odors and pollutants in addition to particles
• ​HEPA filters:​​ Highest level of particle filtration, ideal for allergy sufferers
• ​Washable/reusable filters:​​ Long-term options like K&N's washable filter that can be cleaned and reused

For the 2020 Altima, common filter dimensions are approximately 8.5 inches long, 7.875 inches wide, and 1.375 inches thick, though you should verify specific measurements for your exact model. Genuine Nissan part numbers include H7277-6CA1J, which replaces several earlier versions (27277-5NA1B, 27277-6CA0A, etc.) .

​Step-by-Step Replacement Process:​​

1. ​Prepare the workspace:​​ Open the passenger side door and remove any items from the glove compartment for easier access. Have a flashlight handy for better visibility in the enclosed space .

2. ​Access the filter compartment:​​ Open the glove compartment and locate the retention stops on either side. Carefully detach any damper arm or support mechanism, then lower the glove compartment fully. Behind it, you'll see a rectangular filter cover .

3. ​Remove the old filter:​​ The filter cover is typically secured with clips or small screws. Remove these fasteners and pull the cover forward to reveal the old cabin air filter. Note the airflow direction arrow printed on the old filter—this is crucial for proper installation of the replacement .

4. ​Inspect and clean:​​ With the old filter removed, take a moment to vacuum any debris from the filter chamber. This prevents immediate contamination of your new filter and ensures optimal airflow .

5. ​Install the new filter:​​ Place the new filter into the housing, ensuring the airflow arrow points in the correct direction (typically facing downward or toward the engine compartment). If your filter has an activated carbon layer, the darker colored side usually faces outward .

6. ​Reassemble the components:​​ Replace the filter cover and secure all fasteners. Carefully lift the glove compartment back into position, reattaching any support arms or dampers. Ensure the glove compartment opens and closes smoothly without obstruction .

7. ​Test the system:​​ Start your vehicle and turn the HVAC system to maximum fan speed. Check airflow from all vents and verify that any previous odors have been eliminated. Proper installation will result in noticeably improved air volume and quality .

If you encounter resistance during any step, pause and reassess rather than forcing components. The entire process is designed for straightforward access without requiring excessive force. If your vehicle has a second external cabin filter located near the windshield cowl, consult specific instructions for that additional component .

Choosing the Right Replacement Filters for Your 2020 Nissan Altima

Selecting quality air filters ensures optimal performance and protection for your 2020 Nissan Altima. With numerous options available, understanding the differences helps you make an informed decision based on your driving needs, environment, and budget .

​Engine Air Filter Options:​​

• ​OEM (Original Equipment Manufacturer) filters:​​ Designed specifically for your Altima with guaranteed fitment and performance standards. Nissan part numbers include H7277-6CA1J and its predecessors
• ​Aftermarket premium filters:​​ Brands like Fram, Purolator, and K&N offer high-quality alternatives often with enhanced filtration efficiency or airflow characteristics
• ​High-performance filters:​​ Some brands like K&N offer washable, reusable filters that may increase airflow but typically require special cleaning kits and periodic maintenance

​Cabin Air Filter Considerations:​​

• ​Standard vs. enhanced filtration:​​ Basic particulate filters are sufficient for most drivers, while activated carbon filters provide additional odor reduction benefits
• ​MERV ratings:​​ Higher Minimum Efficiency Reporting Values indicate better filtration of smaller particles—important for allergy sufferers
• ​Brand reputation:​​ Stick with established manufacturers like Denso, FRAM, or STP that meet or exceed OEM specifications

While generic filters may cost less initially, genuine Nissan filters are engineered specifically for your vehicle's airflow requirements and filtration needs. Using counterfeit or poorly constructed filters can lead to reduced performance, increased engine wear, and potentially voided warranties. The small additional investment in quality filters pays dividends through better protection and performance .

Benefits of Regular Air Filter Maintenance

Maintaining clean air filters in your 2020 Nissan Altima provides multiple benefits beyond basic vehicle maintenance. The engine air filter directly impacts performance and efficiency, while the cabin filter affects your driving comfort and health. Together, these components play a crucial role in your vehicle's overall operation and your satisfaction as an owner .

​Engine Air Filter Benefits:​​

• ​Improved fuel economy:​​ A clean filter maintains optimal air-fuel mixture, potentially improving gas mileage by 5-10%
• ​Enhanced engine performance:​​ Unrestricted airflow allows your engine to produce full power when accelerating
• ​Reduced emissions:​​ Proper combustion decreases harmful exhaust emissions
• ​Engine protection:​​ Preventing abrasive contaminants from entering cylinders reduces wear on internal components
• ​Long-term cost savings:​​ Regular filter replacement is far less expensive than repairing contamination-related engine damage

​Cabin Air Filter Benefits:​​

• ​Healthier interior environment:​​ Effective filtration reduces allergens, pollen, and airborne particles that can trigger respiratory issues
• ​Odor reduction:​​ Activated carbon filters specifically capture and neutralize unpleasant smells from outside air
• ​HVAC system protection:​​ A clean filter prevents debris accumulation on evaporator cores and heating components
• ​Improved defogging:​​ Better airflow enhances window defogging efficiency in adverse weather conditions
• ​Quieter operation:​​ A clean system doesn't strain the blower motor, reducing operational noise

The cumulative impact of regular air filter maintenance extends beyond immediate performance improvements. By ensuring your engine receives clean air, you promote complete combustion and reduce carbon buildup on sensors and catalytic converters. Similarly, maintaining your cabin air filtration system protects your HVAC components from excessive dirt accumulation that can lead to expensive repairs. These simple preventive measures represent some of the most cost-effective maintenance you can perform on your vehicle .

Troubleshooting Common Air Filter Issues

Even with proper maintenance, you may encounter issues related to your 2020 Nissan Altima's air filtration systems. Understanding how to identify and address these problems ensures your vehicle continues to perform optimally between scheduled maintenance intervals .

​Common Engine Air Filter Issues:​​

• ​Check engine light illumination:​​ A severely restricted air filter can trigger sensor readings that illuminate the warning light
• ​Reduced horsepower:​​ Engine hesitation or poor acceleration, especially under load, may indicate airflow restriction
• ​Black exhaust smoke:​​ Incomplete combustion due to insufficient airflow can cause visible emissions
• ​Gas smell at startup:​​ Unburned fuel due to rich air-fuel mixture may produce noticeable fuel odors

​Common Cabin Air Filter Issues:​​

• ​Whistling noises from vents:​​ Often indicates a poor seal around the filter or obstruction in the system
• ​Musty odors:​​ Typically caused by microbial growth on a dirty filter—replacement usually resolves the issue
• ​Reduced airflow:​​ The most common sign of a clogged filter requiring replacement
• ​Foggy windows:​​ Inadequate airflow reduces defogging efficiency in humid conditions

If you experience any of these issues shortly after filter replacement, first verify that the filter is properly seated and oriented. Incorrect installation can cause many of the same symptoms as a dirty filter. For persistent problems despite correct filter installation, consult a professional technician to identify potential underlying issues with sensors, blower motors, or other related components .

Maintaining Your Air Filters for Long-Term Performance

Beyond basic replacement, several practices can extend the life and effectiveness of your 2020 Nissan Altima's air filters. Incorporating these habits into your regular maintenance routine maximizes your investment and keeps your vehicle performing at its best .

​Proactive Maintenance Tips:​​

• ​Visual inspections:​​ Check both filters every 7,500 miles or during oil changes—more frequently if driving in dusty conditions
• ​Documentation:​​ Keep records of replacement dates and mileage to maintain a consistent schedule
• ​Seasonal considerations:​​ Replace cabin filters before peak allergy seasons or before summer when AC use increases
• ​Environmental awareness:​​ Recognize that driving conditions (urban vs. rural, construction zones, etc.) significantly impact filter life
• ​Quality components:​​ Always use filters that meet or exceed OEM specifications to ensure proper filtration and airflow

While some sources suggest cleaning and reusing certain filter types, this approach generally isn't recommended for paper filters. Reusable fabric or carbon filters require specific cleaning procedures and must be thoroughly dried before reinstallation to prevent mold growth. For most owners, replacement with new filters provides more reliable performance and better protection .

Conclusion

Regularly maintaining the air filters in your 2020 Nissan Altima represents one of the most cost-effective ways to protect your vehicle's performance, efficiency, and longevity. The engine air filter plays a critical role in ensuring your powerplant receives the clean air necessary for optimal combustion, while the cabin air filter directly impacts the air quality you and your passengers breathe during every journey. Both replacement procedures are designed for straightforward DIY maintenance requiring minimal tools and mechanical experience .

By adhering to the recommended replacement intervals of 15,000-30,000 miles for the cabin filter and 30,000 miles for the engine air filter—while adjusting for your specific driving conditions—you can avoid the decreased performance, reduced efficiency, and potential system damage that result from neglected filtration systems. The simple steps outlined in this guide empower you to take control of this essential maintenance task, saving money on dealership service while gaining valuable insight into your vehicle's operational needs .

Whether you're an experienced DIY enthusiast or attempting your first automotive maintenance project, replacing your 2020 Nissan Altima's air filters provides immediate benefits and long-term protection. With the right parts, basic tools, and approximately 30 minutes of your time, you can ensure your vehicle continues to deliver the performance, efficiency, and comfort you expect throughout its service life.