The Federal Trade Commission's pamphlet on Gas-Saving devices. Read it before you buy.
"Gas Saving" Products:
Gas prices are up, and so is the volume of advertising for "gas saving" products. When gasoline prices rise, consumers often look for ways to improve fuel efficiency. Although there are practical steps you can take to increase gas mileage, the Federal Trade Commission (FTC) warns you to be wary of any gas saving claims for automotive devices or oil and gas additives. Even for the few gas saving products that have been found to work, the savings have been small.
"Gas Saving" Advertising Claims
Be skeptical of the following kinds of advertising claims.
"This gas saving product improves fuel economy by 20 percent."
Claims usually tout savings ranging from 12 to 25 percent. However, the Environmental Protection Agency (EPA) 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 "gas-saving" products may damage a car's engine or cause substantial increases in exhaust emissions. The gas-saving products on the market fall into clearly defined categories. Although the EPA has not tested or evaluated every product, it has tried to examine at least one product in each category. See "Devices Tested by EPA" at the end of this brochure for category descriptions and product names.
"After installing your product on my car, I got an extra 4 miles [6.4 kilometers] per gallon [3.8 liters]."
Many ads feature glowing testimonials by satisfied customers. Yet, few consumers have the ability or the equipment to test for precise changes in gas mileage after installing a gas-saving product. Many variables affect fuel consumption, including traffic, road and weather conditions, and the car's condition. For example, one consumer sent a letter to a company praising its "gas-saving" product. At the time the product was installed, however, the consumer also had received a complete engine tune-up - a fact not mentioned in the letter. The entire increase in gas mileage attributed to the "gas-saving" product may well have been the result of the tune-up alone. But from the ad, other consumers could not have known that.
[Read the rest of this entry...]