To be honest Danz, on the dyno it might not make any difference, and yesterday being so hot it did not feel like it was a huge improvement over stock, but on a cold day, it will make a big difference. The whole concept on this unit is to suck cold air and you have the added value of ramming it from outside. A CAI will suck air that is behind the headlight, so its not rammed onto the pod. This Apollo, I attached a hose so the air comes from directly in front of the car, so all the vaccum is happening fom the front of the car, and when the car is moving, the air is forced inside this tube. On a cold day it will suck up nothing but ice cold air.....and at velocity the air becomes cooler i think (I was bad a physics) so its all beneficial. Being an enclosed unit, its very quite and 100% legal. Its just another option to the CAI. Easy to install and looks very good underneath the engine bay. It's very light and typical K&N the filter unit can be cleaned. As far as being restrictive over a CAI, i dont think it is, the area of the filter is similar, it just doesent make the noise and noise is very deceptive.