Air FilterRound 14 x 4

The Air Filter Round 14 x 4 from GREEN FILTER is a premium reusable cotton intake filter engineered for enthusiasts and mechanics seeking sustained airflow gains without sacrificing engine protection. Unlike disposable paper filters that accumulate restriction over their service life, this round filter design delivers consistent performance across extended intervals, making it a smart investment for both street builds and daily drivers that demand reliability alongside improved throttle response.

This 14-inch diameter cotton construction works through a multi-stage filtration approach that traps particulates while minimizing pressure drop—critical when tuning carburetors or fuel-injected systems where intake vacuum and volumetric efficiency directly influence power output. The 4-inch height profile fits compact engine bays and custom air box configurations, while the washable cotton media can be cleaned with proper filter solvent and re-oiled without degradation, extending service life to years rather than months. Dimensions of 14.35 x 5.05 x 14.6 inches account for mounting flange clearances and hose routing in tight installations.

This filter suits carbureted platforms, turbocharged applications, and naturally aspirated engines where intake manifold temperature stability and air velocity preservation matter. Mechanics often specify it for vintage muscle car restorations, street rod projects, and modern high-performance builds seeking measurable horsepower recovery—typically 5–15 hp depending on baseline restriction and fuel mapping. Verify filter neck diameter and air box opening dimensions before purchase to ensure interference-free fitment; most applications accommodate this 14-inch round design without modification, though custom ducting may optimize cold-air delivery.