Gas Mileage Increasing Devices: Poll.

Attention all gas mileage enthusiasts:

I'm just curious. I checked out the "great auction site in the sky" (can't advertise, so I gotta use code...) Metro Parts and Accessories tonight and found three devices which say they are supposed to increase gas mileage.
1.) A performance chip, whose main boast is to increase horse power. One auction stated that theirs will also increase gas mileage. I emailed them about what percentage of increase to expect. I'm waiting for a response.
2.) A fuel ionizer. It mounts around a fuel intake tube. It's supposed to organize the fuel molecules so that the fuel is burned more efficiently.
3.) An air vortex device. It mounts inside the intake tube between the filter and the intake maniforld. It's like the fuel ionizer in that it organizes the air to organize the oxygen to increase burning efficiency.

I'm hoping some readers have used any one or all three of these devices on their Metros. I'm wondering what kinds of products have been used, their effects on mileage and other results, and if anyone would recommend using any of them. Nice and specific, huh?

Thanks for any helpful info.!!!

Karl

I messed up this poll. Go to the one titled, "Attention all gas mileage enthusiasts!".

I swear by Pixie Dust in the tank. I get 9.8 X 10^23 light-years per microliter of fuel.
Next best is a flux capacitor setup in the trunk.