If fuel economy is a concern, a positive displacement Supercharger (what Magnuson offer) will use more fuel all the time. It will make a lot of power in the low to midrange but will lose out up top to the turbos or centrifugal superchargers, the advantage being positive displacement superchargers are almost lag free and make near their full boost a fraction of a second after you open the throttle enough to close the bypass valve. Just depends what you want, the positive displacement Supercharger will feel like you have a couple extra L of displacement, the turbos or centrifugal need you to get the revs up a bit before they show what they can do so they tend to be similar in the midrange and then take the advantage in the top end. Install wise, Superchargers are much simpler than any turbo kit.