FA-3749 High-Flow Washable Air Filter – Replaces OEM 3749-Style Air Filters

$399.00

High-flow, washable air filter FA-3749

After decades working on heavy-duty diesels, I’ve learned that intake restriction rarely shows up as a sudden failure. It shows up as higher EGTs, lazy throttle response, excess soot, and DPF systems that regen more than they should. OEM 3749 paper filters work fine when they’re new, but once they load with dirt, restriction climbs fast.

That’s why I designed the FA-3749.

This is a high-flow, washable air filter, engineered to maintain airflow over time instead of choking the intake as miles add up. The synthetic filter media resists collapse and airflow drop-off under sustained load, keeping the turbo operating in its efficiency range and combustion stable.

Sealing matters just as much as airflow. The FA-3749 uses OEM-matched sealing geometry so air goes through the filter — not around it. No bypass means better protection for the turbo, charge-air cooler, and engine internals.

Instead of throwing away paper filters every service interval, you wash the FA-3749, oil it correctly, reinstall it, and keep running. One filter replaces years of disposable elements, reduces downtime, and lowers long-term operating cost without sacrificing engine protection.

Compatibility Note:
If your truck or equipment calls for an OEM 3749-style air filter, the FA-3749 is a direct drop-in replacement with no modifications required.

Replaces OEM & Aftermarket Filters

Brand / Category	Filter Part Number or Type Replaced
OEM	3749 Air Filters
OEM / Aftermarket	3749-Style Paper Filters
Aftermarket	Equivalent 3749-Series Intake Filters
Fleet / Fleetguard	3749 Equivalent Filters
Baldwin	3749 Equivalent Filters
Donaldson	3749 Equivalent Filters
Wix / NAPA	3749 Equivalent Filters

Note: Replacement compatibility is based on factory 3749 dimensions and sealing geometry. Exact brand part numbers may vary by catalog.

OEM Cross-Reference Table

OEM / Factory Part #	Application Type	Replaced By
3749	Heavy-Duty Diesel Intake	FA-3749
3749-Style Paper Filter	Class 6–8 Diesel	FA-3749

6. Features & Benefits

Features

High-flow washable synthetic filter media
OEM-matched sealing flange
Designed for turbocharged diesel airflow
Reusable, serviceable construction
Drop-in replacement for 3749-style filters
Built for high-mileage and fleet use

Benefits

Maintains consistent airflow under load
Reduces intake restriction over time
Helps reduce forced DPF regens
Lower exhaust gas temperatures
Improved throttle response
Less downtime from filter replacements
Long-term savings vs disposable paper filters

Competitor Differentiation

Disposable paper filters are designed to be replaced, not to maintain airflow. As they load with dirt, restriction climbs and performance drops.

I built the FA-3749 to hold airflow steady over time, not just look good when it’s clean. Washable media keeps restriction lower, sealing surfaces actually seal, and the filter doesn’t become trash after one dirty service cycle.

Disposable filters keep you buying. A properly engineered washable filter keeps your engine breathing right and your operating costs under control.

Made in the USA!

*Price does not include Klotz Oil*

Fits:

Sterling

If your filter number or truck is not listed please call us at 251.654.0892!