Beware Gimmicks Promising Better Mileage

June 4, 2008 — -- Ever-increasing gas prices are sending motorists in search of sometimes unconventional ways to improve their cars' gas mileage.

Some products are geared heavily toward consumers and promise to make nearly any vehicle more fuel efficient. But "Good Morning America" technology contributor Becky Worley discovered some items may not live up to their fuel-efficient claims, which use additives, reformulators and special magnets as gimmicks.

Check which items Worley found useful and which didn't make the grade.

At $45 per 32-ounce bottle, it claims to increase fuel efficiency between 7 and 19 percent.

What Becky Says

I have not seen any changes in fuel efficiency as a result of adding the liquid to my gas tank. To further my belief that this is a dubious product, when I called some of the distributors listed online for Ethos, the first two numbers were cell phones that were no longer in service and the third had a message saying the person was "locked up" until July 7.

What the Experts Say

The Environmental Protection Agency has evaluated or tested more than 100 alleged gas-saving devices and has not found any product that significantly improves gas mileage. In fact, some so-called gas-saving products may damage a car's engine or cause a substantial increase in exhaust emissions.

The fuel saver's magnet claims it has been tested and approved by an EPA-accepted laboratory to increase fuel economy up to 11.6 percent.

It gives a seemingly scientific online explanation for why the product works, including claims that clustered fuel molecules cause incomplete fuel burning.

What the Experts Say

The EPA has tested all kinds of fuel-line magnets, but no magnetic technology has ever been proven to improve mileage. The science is fundamentally flawed. Fuels in most engines burn at 99 percent efficiency. There's no leftover energy that escapes. Even if the magnets did break up fuel clusters, they'd only be able to improve fuel efficiency by 1 percent.