Scam! This product has been out before...just a different name.Check this out:
http://www.shadetreemechanic.com/tornado_air.htm
The Tornado has been proven not to do anything by third party testers and Mythbusters.
Supposedly it makes your intake air "spin" to help with compression. Really it just slows the air down even more.
I might add too that if you look on that link there is a set of pictures and captions showing the Tornado being placed in a T2000 motorhome and the users will be field testing it and report back. Nothing has been reported back yet and not telling how long that has been up there. Probably because they found nothing happened at all.