I've seen a couple posts for hypermiling. Where they mentioning FAS switch that cuts out your fuel. But I can't find anything as far as where you would purchase one or if it's a homemade thing you just set up and how to set it up. I have a 2007 first gen. And it was just trying to find out more information on this. And before everyone says search the forums I have it seems like the searches almost useless on this site. It just brings up a lot of random posts that has nothing to do with an gas switch.

 

I have never heard of one.

 

Neither have I, until seeing the thread in the General forum just now. It sounds like it's just a switch to disconnect the fuel pump to save fuel. To be honest it doesn't sound like a good idea to me.

 

Honestly it would be great to have. You could basically dead stall your car till you were at a low speed and clutch start it before stopping. With smart driving like this you could boost your mpg by probably 5mpg. I do pizza delivery so I could accelerate to the speed limit cut the fuel and neutral coast to the next stop sign. Then kick the motor on before stopping. The fit already does this when your down shifting to save gas but you'd have more control over it and would have to be spinning the motor and decelerating the whole time. It would really be useful in down hill portions of the road to. There's some areas I could travel a mile or two while using no gas at all given how smoothly the fit glides. A lot of newer cars use this to increase mpg. But it would give you the advantage of doing it manually

 

From what I've been able to gather it directly controls the injectors not he fuel pump so you shut off your injectors for a moment since the motor is drawing no fuel you can be free coasting and shut off the motor then re-engage it with the clutch and adding fuel again. A lot of the hypermilers actually turn off the keys to the car while coasting to save fuel. But that causes other problems like losing power to your vehicle. Or you can stay in a high gear and just shut off the fuel for a while and then turn the fuel back on when it's needed.