Wix 42521 Engine Air Filter - Inner

Engine Air Filter Overview

The Wix 42521 engine air filter is built for heavy-duty air filtration where durable construction and high contaminant capture matter. It uses premium filtration media with metal ends and a corrosion-resistant body to support consistent airflow and service life.

Compatible With heavy-duty air intake systems that use this filter size, the Wix 42521 is a practical choice for routine air filter service. Wix HD Air Filters are recommended for OEM air filter change intervals and are tested to ISO 5011 standards for contaminant removal.

Key Features

• Premium cellulose media for engine air filtration.
• Metal ends and expanded metal body for added durability.
• Pleat stabilization features help maintain media shape where applicable.
• Heavy-duty construction for demanding service conditions.
• ISO 5011 laboratory testing with 99.9% minimum contaminant removal.

Product Details

The Wix 42521 is an HD-style engine air filter designed around a large cylindrical form factor with a 12.500-inch height, 5.700-inch outer diameter, and 4.575-inch inner diameter at the bottom. Its 310 CFM rating supports airflow through the intake system while the cellulose media captures airborne contaminants. This part cross-references NAPA Gold Filters 2521 and Fleetguard AF1767 for the same application.

For buyers searching Wix 42521 engine air filter fitment, this part is a strong match for heavy-duty equipment and commercial applications that require this filter dimensions and construction. The Wix 42521 also aligns with OEM-style service intervals for scheduled maintenance.

What It Helps Address

• Restricted airflow caused by a loaded engine air filter.
• Dust and debris entering the intake system.
• Premature wear from inadequate air filtration.
• Service intervals that call for a heavy-duty replacement filter.

Installation Notes and Quality

Verify the filter dimensions, end style, and housing requirements before installation. Match the Wix 42521 to the existing air cleaner assembly and confirm proper seating to maintain a sealed intake path.

Wix HD Air Filters are built with durable end materials, corrosion-resistant construction, and laboratory-tested filtration performance to support dependable service in heavy-duty applications.