Hello all!
I made a DIY Icebox about two weeks ago. The first 2 days I drove I averaged 26mpg but after that it went back down to 22 mpgs which is what I was getting with the stock intake. Any idea why this happens?

 

Messing with your intake will usually have no measurable effect on your fuel economy. If anything it will be worse because you get on it a bit more. Maybe the first two days you drove super easy with minimal stopping who knows.

James

 

Just putting an icebox with your intake will cause mpg loss, the box will cool the air aking it denser and causing the ECU to put in more fuel.

 

The first night I drove with it I read 28 mpg. Granted I was doing more high way driving than normal but that's a huge difference!

 

I've romped on it about twice or three times but that hasn't had measurable effect on the mpgs. I'm not going speed racer all the time.

 

I think James had it right.
the ECU will control the Air/fuel ratio, always keeping it the same.
there will be no measurable effect on fuel economy.

 

That does make sense. Thanks!