Let's face it- when gasoline prices peaked in 2008, we were hearing about all sorts of things to make our gasoline last longer and go further. There were some gimmicks- the fuel pills were a big one that I already touched on, but what about the additives we find in stores that claim to boost mileage?
You should note that federal law in the United States requires refiners to blend a certain amount of "detergents" or additives to the gasoline they produce. Some refiners have special additives, some market their additives more heavily than others. With the amount of additives in gasoline, store purchased additives are usually not necessary, and many times are bought on impulse.
For those who've walked down the automotive aisle, you know there are literally handfuls of different additives, many claiming to boost your mileage. The U.S. Federal Government even got involved in this- checking the manufacturers claims that their additives boost fuel economy.
From the Federal Trade Commission website:
CLAIM: "This gas-saving product improves fuel economy by 20 percent."
ANSWER: 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.
CLAIM: "After installing your product on my car, I got an extra 4 miles [6.4 kilometers] per gallon [3.8 liters]."
ANSWER: 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.
CLAIM: "This gas-saving device is approved by the Federal government."
ANSWER: No government agency endorses gas-saving products for cars. The most that can be claimed in advertising is that the EPA has reached certain conclusions about possible gas savings by testing the product or by evaluating the manufacturer's own test data. If the seller claims that its product has been evaluated by the EPA, ask for a copy of the EPA report, or check www.epa.gov for information. In some instances, false claims of EPA testing or approval have been made.
In closing, there are many ways to enhance your fuel economy, many of them happen to be very simple, such as changing your driving habits, or keeping your vehicle maintained. Before wasting money on additives, it would be a good idea to test your fuel economy using proven methods.