I saw an article for a device that improves fuel economy it mounts on your dash and looks like a radar detecor

Question

There are green, yellow and red lights. If you brake or accelerate to hard the lights go from green to yellow to red. It is not wired or connected directly to your car. Has anyone else seen or know anythig about this item?

Answer 1

One of the major magazines tested the device in question and I read the report-I think it was Car and Driver.  In general the device is really just a motion sensitive potentiometer-probably with a mercury switch which operates the lights.  In short-it can tell if you are braking hard, accelerating hard or having too much fun which leads to wasting gas.  It proved to gain 2-3 mpg.

Answer 2

If you're also interested, I can sell you the Brooklyn Bridge.

Ignore these gadgets which make crazy claims of improved fuel economy.  

Heck, may as well get the Tornado for $20 ... it's supposed to add 20 hp to your engine.

Answer 3

all it does is detect when your braking or accelerating hard.

you could do the same by putting a glass of water in your cup holder.

if it spills your braking too hard.

drive more smoothly and save your money.

Answer 4

The device itself does not do anything. What it does is it helps you tell when you are wasting fuel, thus help you change your habits to use fuel better. That device does nothing mechanical, it is a behavior modifier.

Answer 5

So your willing to spend money on something you can do all buy yourself for free. I have some ocean front property in New Mexico I would like to talk to you about.