Has anyone ever used the Green brand cold air intake system. I saw one the other day and I'm considering getting it. What gains does it give, such as horsepower and mileage?

 

If the filter is not completely enclosed, like in a Volant system, you might as well go the much cheaper 14x3 round intake route.

As far as HP and MPG, it will give you twenty more ponies and 5mpg increase. Just kidding. You're, realistically, looking at single digit HP increase, depending on your other mods, and you'll be lucky to get 1-2mpg increase. The main thing you will notice is how much faster the pickup will accelerate.

My problem once I got my Volant installed was keeping my lead foot off the pedal, since it had much better acceleration. My MPG actually stayed the same, maybe even went down 0.5 because that first week I couldn't stop my stupid foot.