Fleetguard
NanoNet Fuel Filter FF5971NN Fleetguard 6-Pack — Cummins X15 X12 5575143
NanoNet Fuel Filter FF5971NN Fleetguard 6-Pack — Cummins X15 X12 5575143
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Fleetguard FF5971NN NanoNet Fuel Filter 6-Pack — Genuine OEM 4-Micron Extended-Life Filter for 2020+ Cummins X15 & X12 Engines
The Fleetguard FF5971NN 6-Pack is a case of six genuine Cummins Filtration NanoNet spin-on fuel filters designed for 2020 and newer Cummins X15 and X12 engines with EPA 2017 and EPA 2021 emission ratings. This is the MOST ADVANCED fuel filter in the Fleetguard lineup — featuring proprietary NanoNet synthetic media that delivers 4-micron filtration at 99.2% primary particle efficiency, providing the finest fuel filtration available for Cummins heavy-duty diesel engines.
The FF5971NN's headline feature is its 75,000-mile service interval — three times longer than the standard FF5776 (25,000 miles). This extended service life means fewer filter changes, less maintenance downtime, and lower total cost of ownership for fleet operators. The NanoNet media holds significantly more contaminant at consistent differential pressure compared to the older StrataPore (FF5776) and first-generation NanoNet (FF5825NN), delivering sustained protection throughout the entire extended interval.
The FF5971NN is the direct replacement for Cummins OEM 5575143 and is backwards-compatible with FF5825NN — meaning it fits the same M90 x 2-7H mount. However, it is 2.6 inches TALLER than the FF5776 (11.5" vs 8.9"). Verify clearance before upgrading from FF5776. Trusted by fleet managers, owner-operators, and diesel shops running 2020+ Freightliner, Kenworth, Peterbilt, International, and Volvo trucks with Cummins X-Series engines.
Technical Specifications
| Specification | Value |
|---|---|
| Part Number | FF5971NN |
| Brand | Fleetguard (Cummins Filtration) |
| Filter Type | Spin-On Secondary Fuel Filter |
| Media Type | NanoNet Synthetic |
| Micron Rating | 4 Micron (c) @ 99.2% Primary Particle Efficiency |
| Overall Height | 292.1 mm (11.5 in) |
| Largest Outside Diameter | 120.3 mm (4.736 in) |
| Gasket Inside Diameter | 101.6 mm (4.0 in) |
| Gasket Outside Diameter | 120.3 mm (4.736 in) |
| Thread Size | M90 x 2-7H |
| Thread Form | Metric |
| Rated Flow | 4 L/min |
| Hydrostatic Burst Minimum | 874.77 psi |
| Filter Position | Secondary (high-pressure side) |
| Service Interval | 75,000 miles (duty cycle dependent) |
| Backwards Compatible With | FF5825NN (same M90 mount) |
| Upgrades/Replaces | FF5825NN, FF5776 |
| Quantity | 6 Filters Per Box |
Compatible Engines
| Engine | Emission Rating | Years |
|---|---|---|
| Cummins X15 | EPA 2017, EPA 2021 | 2020+ |
| Cummins X12 | EPA 2017, EPA 2021 | 2020+ |
| Cummins ISX15 (late production) | EPA 2017 | 2020+ only |
| Cummins ISX12 (late production) | EPA 2017 | 2020+ only |
Important: The FF5971NN is for 2020 and newer Cummins X15/X12 engines. Pre-2020 ISX15/ISX12 engines use the FF5825NN or FF5776. Always verify your engine serial number and emission certification (EPA17 or EPA21) before ordering.
Compatible Trucks
| Truck Brand | Models |
|---|---|
| Freightliner | Cascadia (2020+), Coronado, 122SD, 114SD |
| Kenworth | T680 (2020+), T880, W990 |
| Peterbilt | 579 (2020+), 567, 389 |
| International | LT Series, HX Series (with Cummins X15) |
| Western Star | 4700, 4900, 5700XE, 49X (2020+) |
| Volvo | VNL (with Cummins X15, 2020+) |
Cross-Reference Part Numbers
| Cross-Reference | Brand | Verified Source |
|---|---|---|
| 5575143 | Cummins OEM | AllProDiesel.net, Amazon, PartAndFilters.com |
| BF46248 | Baldwin | AtYourPlaceRepair.com |
NOTE: The FF5971NN is a NEWER product with LIMITED aftermarket cross-references. Most aftermarket brands have not yet released equivalents. The Cummins 5575143 and Baldwin BF46248 are the only verified cross-references as of June 2026. Your competitor incorrectly lists P550933 (Donaldson for FF5776), 33674 (Wix for FS19764), 3674 (NAPA for FS19764), and BF46002 (Baldwin — unverified) as cross-references. These are WRONG.
FF5971NN vs FF5825NN vs FF5776 — Upgrade Path
| Feature | FF5776 (Original) | FF5825NN (1st NanoNet) | FF5971NN (This Product) |
|---|---|---|---|
| Media | StrataPore (cellulose) | NanoNet (synthetic) | NanoNet (advanced synthetic) |
| Micron Rating | 5 micron | ~4 micron | 4 micron @ 99.2% |
| Service Interval | 25,000 miles | 25,000-50,000 miles | 75,000 miles |
| Height | 226.5 mm (8.9 in) | 226.5 mm (8.9 in) | 292.1 mm (11.5 in) |
| Thread | M90 x 2-7H | M90 x 2-7H | M90 x 2-7H |
| Engine | All ISX (2010+) | All ISX/X15 | 2020+ X15/X12 ONLY |
| Backwards Compatible | — | Replaces FF5776 | Replaces FF5825NN |
All three share the same M90 x 2-7H mount and are physically interchangeable, but the FF5971NN is 2.6 inches taller than the FF5776 and FF5825NN. Verify engine compartment clearance before upgrading.
When to Replace
The FF5971NN is designed for 75,000-mile service intervals under normal operating conditions. Actual interval depends on duty cycle, fuel quality, and operating environment. Replace sooner if you observe loss of power under load, extended cranking, fuel-restriction fault codes, or reduced fuel economy. For severe-duty applications (construction, mining, extreme temperatures), consult your Cummins dealer for adjusted intervals.
What's Included
6x Fleetguard FF5971NN NanoNet Fuel Filters — individually boxed or securely bulk packed in OEM Fleetguard packaging. Each filter is genuine Cummins Filtration with NanoNet media, not aftermarket or repackaged.
Why Choose the FF5971NN Over the FF5776 or FF5825NN?
The FF5971NN represents Fleetguard's latest advancement in fuel filtration technology. With a 75,000-mile service interval (3x longer than FF5776), a single FF5971NN eliminates TWO additional filter changes, saving labor time, parts cost, and vehicle downtime. The advanced NanoNet media captures 99.2% of particles at 4 microns — finer than the FF5776's 5-micron rating — providing superior injector protection for modern high-pressure fuel systems operating at 36,000+ PSI. For 2020+ Cummins X15 and X12 engines, the FF5971NN is the factory-specified filter that maximizes both protection and service efficiency.
