Hey guys, my girlfriend's father bought a mint condition 2000 Ford F-150 with the 5.4L V8. The previous owner put an aftermarket airbox and filter. Not sure if it's tuned, but I'm assuming not.

With just the aftermarket, will that affect gas mileage? It has an aftermarket K&N Cone Filter and air box. He uses it to travel from Miami to Orlando and back on occasion, so a decent MPG is wanted over HP. Will he save any MPG is he reverts to a stock filter and air box? I'll see if I can take a photo of the set up next time he's in town. I'm not sure how a stock set up looks like, so its possible the intake tube is also aftermarket.

Where can we get a decent stock air intake set up? Any reputable stores/websites? Or best bet junk yard?

 

your best bet is directly from ford or a junkyard.

 

I thought high flow filters were supposed to improve MPG.