Gas Saving Devices save gas?

Tip: Gas Saving Devices save gas?

The U.S. government agencies haven't approved that gas saving devices can save gas and boost mileage up yet. However, advertisements on the Internet, radios, or newspapers have claimed gas saving devices do save gas.

Many gas saving devices don't work. If you really would like
to try one, ask the seller if it can refund the money in case
it doesn't work. Make sure you keep the purchase receipt. It
might not be easy to get your money back if you purchase the
gas saving device online or by mail order.