I just installed a Volant cold air intake on a 2005 Expedition, 5.4V8 4x4. It did help with performance. The truck just gets around easier now. You step on the gas and it goes. The air filter is enclosed in a sealed box. I'm no expert here, but they tell me this helps keep it from being to loud. This is different from a lot of the other companies. Volant claims 16 horsepower and 18 ft lbs. of torque increase. I believe it. After running a few tankfulls of gas through the truck, my average mileage went from 13.4 to 14.1. Does this help? Oh, I bought through autoanything.com. I had a very good experience. They also have lots of reviews. I was not sure what to do and never done anything like this before. So, I called Volant. They were great to talk to and answered every dumb question I asked.