No!  Let me put it this way, No!   Most of these have been around since the automobile was first invented, but as time goes by they have a new audience.  Just keep your tire pressure at the correct level (psi) and drive easy if you want better MPG.

I just filled up today and I got 27.5 mpg, all city driving for me. 

The tornado: NO

K&N filter: Yes

Cold AIr intake: Yes

Intake will do more then just the filter. Used to be that installing a upgraded ingnition made a huge difference. Now adays the whole system is computer controlled so all you can really do is change the chip or reprogam it.

Ive used K&N drop ins and just took out my TRD drop in. No difference at all in gas mileage. Cold air works if you dont jump on the pedal all the time, my gen1 with an aem cold air was getting like 32mpg. Years ago, more like 15 yrs ago, I used to be a Tornado dealer and yes that really works. Its not significant change, more like 1-3 miles more per gallon. But this is all in refection of how you drive, whatever things you put in, if you jump on the gas pedal all day long, you're not going to get great gas mileage. The tests they do to prove it works, the guy doesnt really drive like we do everyday, he slowly accelerates, he drives like a grandma. So sure it works if you put it that way.

Ive added a Sun hyper voltage system with ground wires, that actually save about 1.7 mpg on my turbo charged Evo 8. On my G35, maybe 1.2 mpg. Im adding one to my new B next week, so I guess we will see.

I actually bought one of those "Bogus MPG Gadgets." I bought the "Gas-Saving Tornado for my 2004 Hyundai Elantra. I will tell you my engine got louder, more responsive, and about half-a-mile better in MPG.

Isn't that tornado thing similar to the throttle body spacer which "increases" HP?

I have invented a fuel saving device that is a major technological breakthrough in combustion engineering.  Called the "Eco Pedal", it is far more effective than pills, magnets or whirlybird type devices.  The Eco-Pedal replaces the stock accelerator with an aftermarket pedal that includes a solenoid to provide increased resistance the harder you press.  Eventually your calf muscles cramp up so bad that you just leave your car in the garage and bum a ride with somebody else.  Scientific testing has shown that gas mileage can improve as much as 5000% depending on how much you used to drive. 

We could have achieved the same results with a big-assed spring, but that wouldn't have justified the $149 price tag (plus installation).  We are currently establishing our nationwide dealer network and you'll soon be seeing cheesy ads with outrageous claims and fake testimonials in the back of your favorite automotive publicaions.  If you are interested in getting in on the ground floor of this fantastic moneymaking operation, send me $2500 in cash for an official Eco-Pedal Authorized Dealer Package.  Act now to lock in your exclusive Eco-Pedal dealer territory!

I am sorry to inform you that just last week I assigned all rights to the Carribean market to a Mr. Mbuhtu Muhma Muhtamba, son of the Director of International Commerce in Nigeria for double your offer.