Deal or Dud?

I am not an auto mechanic nor do I want to be. But there are some things about automobiles that intrigue me (and frustrate me as well), such as why does the gas mileage go down as the vehicle gets older? You start out with a brand new car getting 20 MPG and 5 years later you are down to 11.3? Really makes no sense to me. So I posed this question to some friends on Facebook and was told to do all sorts of things- change this, change that, clean this, clean that. I was really looking for a more simple solution, short of buying a new car of course.
Here comes the simple solution. We found on the internet a gas mileage enhancing chip from a company called GForce (http://www.gforcecchips.com/) . I was a little leery at first when I was informed we just purchased this nifty little gadget that was "supposed" to increase your gas mileage. I thought "sure, one more scam we have just been sucked into that offers all these claims yet no performance". So yesterday, "Increase Your Gas Mileage Chip" goes on car.
This morning, as I start my car with much anticipation (I know, it takes very little to excite me), I can't wait to put this thing in drive and see if it is what it is cracked up to be. Amazingly the little digital numbers that tell me what my MPG is, has increased! Now, it wasn't up to 20 MPG or anything like that, just a mere 14.1, but hey, it is better than 11.3 right?? As of right now, I am pleasantly surprised with this little find and I would consider it a deal, but it IS only one day in use. I will have to get back on this once it has been on over a period of time. But now I am thinking...if I change this, change that, clean this, clean that ALONG with the chip, how much more MPG can I get??


P.S. I am still looking for a chip to place in husbands and children that might help them with cleaning. Will let you know what I find.