Originally posted by 56kz2slow:
Here is some good reading on various devices that are sold claiming to give performance and mpg boosts:

http://www.popularmechanics.com/automotive/new_cars/1802932.html

We say caveat emptor (let the buyer beware). But there are plenty of people out there who say: "There's one born every minute." Prediction: Within a few weeks after the appearance of this article, there will be gas-saving gadgets on the market that tout themselves as "Featured in Popular Mechanics." Someone will buy them. Probably not you.