Gained 1+ mpg City and almost 2+ mpg highway.

[Mr Big]

How closely were you drafting the semi ahead of you?

 

[techdude99]

I found as long as you keep the tire pressures set to the OEM spec and drive in a way that keeps you out of boost most of the time, your gas mileage will improve dramatically.

Because the Expedition is basically a huge box aerodynamically, keeping it at 65mph or under on the highway will make a big difference, too.

I tried a lot of different air filter brands over the years with various vehicles and always found OEM to have the best filtering properties. That's my 2 cents

 

[nationalgallery]

That wooshing noise you here isn't horsepower, it is your money being sucked out of your wallet.