In a stuffy Marina del Rey hotel meeting room Thursday night, Taylor Rivera spoke excitedly about a gas-saving additive he'd discovered a few months before.
"I normally get 255 miles to the tank," said Rivera, who drives a Porsche SUV. After popping the gas additive BioPerformance Fuel into his tank several times, he said, "my mileage jumped up to 305. I didn't research it, but it worked for me, so I shared it with my friends."
Using colorful anecdotes, Rivera and three of his friends who also were there to tout the product told the small audience how they increased their mileage 10% to 30% using BioPerformance.
But neither Rivera nor his friends could explain how BioPerformance Fuel lowered emissions or increased gas mileage, citing only anecdotal evidence and referring questions to the company's website. They could not provide the corporate office's phone number -- which was also not available on the website -- explaining that the company does all of its business online.
Rivera is one of many independent distributors around the nation selling BioPerformance Fuel, which is sold in a pill or powder. According to its website, BioPerformance Inc., with corporate headquarters in Irving, Texas, started in December 2005 and claims to have made more than $25 million in sales.
Skyrocketing gas prices have helped drive an industry promising better fuel efficiency in the form of pills, liquid additives and devices. There are fuel-line magnets that claim to change the molecular structure of gasoline and gas pills that increase the "calorific power" of a car's fuel system.
But auto experts, the Federal Trade Commission and the Environmental Protection Agency have expressed skepticism about products that claim dramatic gas savings.
"Every year, when we go through a price increase in gasoline, there's a surge of interest in fuel economy enhancement devices," said Steve Mazor, director of the Automobile Club of Southern California's Automotive Research Center, which tests about a dozen products each year. "Most of the products that we test just plain don't do anything at all."
This year, with gas prices at more than $3 a gallon, Mazor said the organization had received more calls from consumers and manufacturers regarding gas-saving products.
The EPA has tested more than 100 products and add-on devices, finding most to be ineffective, said spokesman John Millett. In a few cases, products were found to increase exhaust emissions, potentially violating federal law on emissions tampering, according to the agency.
Companies must register their products with the EPA to ensure that the additives or devices won't harm engines or increase emissions, but that registration is not an endorsement of the products, Millett said.
The myriad devices on the market work in a variety of ways: bleeding air into the carburetor, heating the fuel, enhancing the vaporization of the air-fuel mixture, to name a few. In 2005, Consumer Reports tested three products -- Tornado, Fuel Genie and Platinum Gas Saver, with prices ranging from $70 to $119 a pop -- and found that none of them enhanced fuel economy significantly.
"The EPA recommends strong skepticism for consumers, because in our experience these things just don't work," Millett said. "If they worked, cars would be built that way anyway."
The Federal Trade Commission has filed numerous lawsuits against companies that made unsubstantiated claims. "When the FTC tells companies they must have scientific proof, anecdotes don't cut it," said Laura J. DeMartino, an FTC attorney.
Although some of the products might improve your car's mileage, your best bet is to go to a trusted auto mechanic and determine whether it is a practical and cost-effective option, said Peter MacGillivray, vice president of communications at the Specialty Equipment Market Assn., a trade group representing the $32-billion auto accessories industry.
Many liquid additives have also been found to be washouts, experts say. Some additives include chemicals such as toluene or ethanol, already present in some formulations of gasoline, yet are often more expensive than regular gas, Mazor said.
And in some cases, too much of a good thing can be harmful to your car.
Ethanol, which can be produced from corn, is already added to many gasoline formulations in a concentration of about 10%.
Most fuel tanks are designed to withstand no more than that amount of the corrosive alcohol, said Philip Reed, consumer advice editor at Edmunds.com, an automobile advice website. Adding more to your tank in the form of additives "can attack certain seals in the fuel delivery system," he said.