Mike, quite a long reply. I am impressed with your effort, but not the product. The online videos are, well, pathetic. There is no science in your web sites and lots of smoke and mirrors. Taking the web site down could actually help your sales.

A video you should watch is "Tommy Boy".

"You can put crap in a box and put a warranty on it, but wouldn't you rather get a quality product instead?"

A money back warranty is meaningless.
Every late-night TV get rich quick scheme comes with one.
( I think this is the only reason the FTC allows the items, like yours to be sold in the first place... )
Every item sold at Wal-Mart comes with a MBG even though it is mostly cut-rate crap from China. But such a very small % of people return stuff, Wal-Mart has nothing to fear.

I feel you, like them, are banking on the fact that 90% of all purchasers will be too embarassed to return a product that scamed them out of hundreds, or thousands of $. People do not like to admit to themselves they were stupid enough to buy. You are feeding off human nature, not a quality product IMHO.

Your product will in most cases give single-digit % increases in fuel economy at best, and is in no way worth the cost. There is usually a thread of truth that gets people motivated to get such a project rolling, but the effects are so minor, you best save your cash for something else.
Great claims require indisputable proof. Where is it? Tell me your converter helps boost FE by 6% and I may believe you.

I bought a Hybrid car, even though they cost more, because I could see and measure the results, but even then, it takes years to get a return on the investment.

Nice try. Nice effort. Weak product, (based on weak website info) IMHO.