Has anyone tried one of them ebay performance modules and vortex thingys?

I was lookin' around on Ebay for parts for my 03 is 300 and I be seein' them gas saving, hp boostin' modules so i was wondering if they work cuz my is 300 eats hella gas, it's like 25mpg on the freeway and 18 in da city, how bout the vortex(tornado) thingy anyone got that?

It's snake oil. If it really helped, Toyota would be all over it and it would be in every vehicle.