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Drop-In Replacement Air Filter for aFe Momentum Intakes That Needs No Oiling
The aFe AFE20-91211D is the Magnum FLOW Pro DRY S replacement air filter in size 3-1/8 inch flange, 6 inch base, 4.5 inch top inverted, and 6.25 inch height. An oil-free, dry synthetic media filter designed for use in aFe Momentum air intake systems, the AFE20-91211D delivers high airflow with no re-oiling maintenance, replacing the oiled gauze filter in compatible Momentum intake housings with a clean, hassle-free alternative.
Key Features
- Pro DRY S Synthetic Media: The AFE20-91211D uses aFe's three-layer progressive synthetic media that provides high filtration efficiency and high airflow without requiring oil, eliminating the mess and uncertainty of oiled filter maintenance
- No Oiling Required: Unlike aFe's Pro 5R oiled gauze filters, the AFE20-91211D Pro DRY S media is permanently dry, making it ideal for owners who want a set-and-forget replacement filter
- Drop-In Replacement: The AFE20-91211D is engineered to the exact dimensions of the aFe Momentum intake housing it replaces, with a 3-1/8 inch flange for a tight, vibration-free seal against the intake tube
- Washable and Reusable: The synthetic media can be cleaned with aFe's dry filter cleaner, dried, and reinstalled without purchasing a new filter
- Three-Layer Progressive Media: The graduated density media layers capture larger particles at the outer layer and finer particles deeper into the media, maximizing both flow and filtration efficiency
Specifications
| Detail | Value |
|---|---|
| Part Number | AFE20-91211D |
| UPC | 802959214879 |
| Filter Type | Pro DRY S (oil-free synthetic) |
| Flange Diameter | 3-1/8 in (inner, inverted) |
| Base Diameter | 6 in |
| Top Diameter | 4-1/2 in (inverted) |
| Height | 6-1/4 in |
| Media Layers | 3 |
| Oiling Required | No |
| Washable | Yes |
| Fitment | Universal (aFe Momentum intakes) |
What's Included
- 1x aFe AFE20-91211D Magnum FLOW Pro DRY S replacement filter
About aFe Power
aFe Power is a California-based performance parts manufacturer specializing in intake systems, exhaust components, and air filters for domestic and import vehicles. The Momentum intake line and Magnum FLOW filter family are among aFe's most widely installed products across the truck, SUV, and sport compact segments. aFe develops all of its filters in-house using proprietary synthetic and gauze media technology, with full dyno testing conducted at their Southern California facility.
Frequently Asked Questions
What is the AFE20-91211D?The AFE20-91211D is the aFe Magnum FLOW Pro DRY S replacement air filter in a 3-1/8 inch flange, 6 inch base, 4.5 inch inverted top, 6.25 inch height configuration. It is an oil-free synthetic media filter used as a replacement element in compatible aFe Momentum air intake systems.
Does the AFE20-91211D require oiling?No. The Pro DRY S designation means this filter uses permanently dry synthetic media. It requires no oiling before installation or after cleaning, making it a lower-maintenance alternative to aFe's Pro 5R oiled gauze filters.
Is the AFE20-91211D a direct replacement for my existing aFe Momentum filter?Yes, if your existing Momentum intake uses a filter with the same dimensions (3-1/8 inch flange x 6 inch base x 4.5 inch top inverted x 6.25 inch height). Verify your current filter's dimensions or part number before ordering to confirm the AFE20-91211D is the correct replacement size.
Can I clean and reuse the AFE20-91211D?Yes. Clean the AFE20-91211D with aFe's designated dry filter cleaner. Spray, let soak, rinse with low-pressure water from the inside out, and allow to air dry completely before reinstalling. Do not use compressed air to dry, as it can damage the media fibers.
How does Pro DRY S compare to Pro 5R in terms of flow and filtration?Pro DRY S provides very high airflow and excellent filtration without the variability that comes from improper oiling of gauze media. Pro 5R oiled gauze filters typically show slightly higher flow on a dyno test, but in real-world daily use the difference is minimal and Pro DRY S eliminates the risk of over-oiling that can damage MAF sensors.
Will the AFE20-91211D fit non-aFe intake housings?The AFE20-91211D is dimensioned for aFe Momentum intake housings but may fit other cone-style intake housings that accept a 3-1/8 inch flange cone filter with similar base and top dimensions. Verify the flange diameter and cone dimensions of your housing before assuming fit.
Does the AFE20-91211D void my vehicle warranty?Under the Magnuson-Moss Warranty Act, a dealer cannot void a vehicle warranty solely due to aftermarket parts unless the dealer can demonstrate the aftermarket part caused a specific failure. An air filter replacement alone does not void a powertrain warranty.
What is the service interval for the AFE20-91211D?aFe recommends cleaning the Pro DRY S filter every 30,000 miles under normal driving conditions, or more frequently in dusty or high-debris environments. Inspect the filter during every oil change and clean if significant dirt loading is visible.
Installation Instructions
- Locate the existing air filter element inside your aFe Momentum intake housing.
- Loosen the clamp or release the clips holding the filter to the intake tube flange and remove the old filter element.
- Inspect the inside of the intake housing and wipe out any loose debris or dust before installing the new filter.
- Insert the AFE20-91211D flange end onto the intake tube, ensuring the rubber flange seats fully and evenly around the entire circumference.
- Tighten the clamp to secure the filter to the intake tube. Do not over-tighten, which can deform the flange rubber.
- Check that there is no air gap between the filter flange and the intake tube before reinstalling any housing panels.
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