They don't even have to be. I have bad mpg and it is badly designed. Doesn't draw cold air. It draws in hot air from the engine bay causing my Explorer to overheat. I returned the factory intake and the gpm are back up and it's not starting to overheat on the track. Udder shit.
69 1018TS Performance Intake Kit
9 Review
π K&N Cold Air Intake Kit: Boost Horsepower on 2015-2016 Ford F150 Turbo Ecoboost, 3.5L V6, 63-2592
9 Review
π§ Improved Performance: K&N Cold Air Intake Kit for 2007-2009 FORD Mustang GT (63-2565)
9 Review
π§ Enhance Performance with Spectre 8711 Vacuum Sensor Adapter Kit
9 Review