If your aim is more power and you take advantage of that extra power then yes, you will use more fuel. However, if the engine doesn't have to work as hard to produce the same amount of power you have upped the efficiency.lonlawrence said:AndrewGS, I see you replying (arguing with) all my statements. You're all wet. While a particular engine may be designed to run at a given mpg, increasing the airflow will increase the fuel flow. You know nothing about thermodynamics or the computers used in our modern autos. I repeat, TO GET MORE POWER, YOU HAVE TO THROW MORE FUEL ON THE FIRE. MPG AND POWER DO NOT GO HAND-IN-HAND. IF YOU GET MORE POWER OUT OF A GIVEN ENGINE, YOU HAVE TO BURN MORE FUEL "IN THAT ENGINE." CHANGING THE ORIGINAL CONFIGURATION OF THE ENGINE WILL AFFECT YOUR FUEL MILEAGE. I HAVE 45 YEARS EXPERIENCE AS AN ASE MECHANIC AND I HAVE BUILT MORE HOT-RODS THAN YOU HAVE EVER SEEN SEEN. GET REAL!
I have a ram-air intake and Corsa exhaust on my 5.3L Silverado and driving efficiently I get 2MPG better than stock (3MPG better on the highway) because it's not working as hard to pump the air in and out.