The K&N 57-2591 is a 57 Series FIPK (Fuel Injection Performance Kit) for the 5.0L V8 in 2015–2017 Ford F-150s. The K&N 57-2591 performance air intake contains a custom rotationally-molded tube and a large filter to provide a guaranteed increase in horsepower. The tube is made from high-density polyethylene, and the system uses a heat shield to keep the filter away from engine-bay heat. The manufacturer lists an estimated gain of 12.74 HP @ 4555 RPM, and the kit is legal for use in all 50 states.
Compared with a cheaper bolt-on filter, the appeal is that this kit replaces the factory intake tube and filter together rather than only swapping the element. The filter is oiled cotton and washable, and the manufacturer states it only needs cleaning every 100,000 miles under normal highway driving conditions, which can offset the cost of repeat disposable filters. Be aware that some user forum members argue that the promised gains from the K&N are close to nothing. Any oiled filter increases the risk of contaminants accumulating on the many sensors located in the intake tract. Weigh those concerns against the warranty and your own goals before buying.
Fitment is listed for the F-150 with the FORD F150 V8-5.0L F/I, 2015-2017 application, so confirm model-year coverage with the manufacturer before ordering for any other year. Owners report easy installs; one owner on the manufacturer's review page said just installed on my 2015 f150 5.0. Very easy to follow instructions even for a non mechanic. Total installation time was 35 minutes. Buyers searching for a 2015 F-150 5.0 cold air intake, FIPK install, washable oiled filter, or MAF-compatible intake upgrade will find this a direct-fit option.
The manufacturer lists this kit for the 2015–2017 Ford F-150 with the 5.0L V8. Published details vary on whether other years are covered, so confirm application with the manufacturer before ordering.
The manufacturer states the washable filter only requires cleaning every 100,000 miles under normal highway driving conditions.
The manufacturer lists a CARB Executive Order number, D-269-64, and states the kit is legal for use in all 50 states.
The manufacturer states that a typical installation can be completed in 60 minutes or less using simple hand tools, and it supplies an installation instruction sheet with the kit. Owners on user forums report similar timing, with one describing an install of about 35 minutes. Because the system replaces the factory intake tube and air box filter, plan to disconnect the mass airflow sensor and the intake-related hoses and clamps carefully, and reuse the kit's five stainless steel clamps as the instruction sheet directs. Disconnect the battery before starting, and recheck all connections for tightness and alignment before the first start.
