With the average price of a gallon of regular gas soaring to $2.68, drivers are looking for any way to cut down on costs at the pump.
Consumer groups, however, warn promotions promising quick fixes are usually too good to be true.
One of the latest ads sweeping the Internet is a "gas pill" marketed by Fuel Freedom International. Fuel Freedom International says dropping a $2 MPG-Cap in your tank with every fill up will increase mileage by 10 percent or 20 percent. When ABC affiliate WPVI asked a AAA expert to test-drive the pill, results were not as significant.
AAA saw no improvement while driving at 34 mph and just a 4 percent increase in mileage at 65 mph.
The company recommended a bigger dose, but when AAA used four pills in the tank, it didn't make a difference.
"I didn't see anything approaching any of the claims for 10 [percent], 20 [percent] or 30 percent improvement in mileage," said Tom McLaughlin of AAA.
The company suggested McLaughlin might have to burn several tanks of gas before the pill kicked in. Fuel Freedom International did not return "Good Morning America's" calls for comment.
The Environmental Protection Agency has not tested MPG-Caps, but it has tested more than 100 other gadgets and additives that say they will save gas and has found they do not work.
"Those kind of claims, we have yet to find any kind of device or additive that can produce that type of result," said Joni Lupovitz of the Federal Trade Commission.
In 2005, ABC investigated a $90 million magnet that attached to your fuel line and was supposed to increase mileage by 27 percent. Lupovitz said when the product was tested, it was found to be bogus. The FTC sued the company, which agreed to pull its ads.
"We really want marketers to know we're watching them. We're monitoring the airwaves and the Internet and the print ads, and that we will take action if we see something that's egregious," Lupovitz said.
There may not be a quick fix for high gas prices, but there are some simple steps to improve gas mileage:
Keep your car tuned up
Slow down and avoid a lot of jerky starts and stops
Make sure your tires are properly inflated
Remove excess weight from the trunk
If you typically drive 12,000 miles a year, these simple steps could save you up to a couple hundred dollars.
ABC consumer correspondent Elisabeth Leamy reported this story for ABC News.