The K&N 57S-4000 Performance Airbox replaces the restrictive factory air filter and air box lid. K&N performance air boxes are designed to dramatically reduce air flow restriction as well as smooth and straighten air flow. This allows your engine to inhale a larger amount of air than the factory air filter assembly. More air means more usable power and acceleration throughout the engine's RPM range. The 57S-4000 Performance Airbox comes with an oversized conical K&N high-flow air filter and an injection molded air box lid with the K&N logo embossed on top. The air filter can be used for up to 100,000 miles before servicing is needed depending on driving conditions. This performance air box is relatively easy to install into the air box base with commonly available tools. K&N builds these air box systems to last for the life of your vehicle and they are backed by K&N's Million Mile Limited Warranty. Some K&N 57S Series Performance Airboxes are compliant with the latest TUV emissions and sound regulations. Check the K&N catalog or website for vehicle applications and specific TUV status for each vehicle and air intake.
Installation Instructions
Installation Instructions


This Part Fits:

Year	Make	Model	Submodel
2017	Ford	C-Max	Energi SE
2013-2016	Ford	C-Max	Energi SEL
2017	Ford	C-Max	Energi Titanium
2013-2017	Ford	C-Max	Hybrid SE
2013-2016	Ford	C-Max	Hybrid SEL
2017	Ford	C-Max	Hybrid Titanium
2016-2018	Ford	Focus	RS
2013-2015	Ford	Focus	S
2013-2015	Ford	Focus	SE
2013-2018	Ford	Focus	ST
2013-2015	Ford	Focus	Titanium
2014-2016	Ford	Transit Connect	Titanium
2014-2016	Ford	Transit Connect	XL
2014-2016	Ford	Transit Connect	XLT