Aftermarket fuel economy device

An aftermarket fuel economy device is a device sold on the aftermarket that claims to improve the fuel economy and possibly the fuel emissions of a vehicle. There are a large variety of devices sold under names such as "Platinum Gas Saver", "Tornado Fuel Saver", "Cyclone-Z", "Atomized Vapor Injector", or "Turbo-carb".

There are several different designs, but many are designed to fit on the intake or carburetor of a car and purportedly optimize air or fuel flow in some way. They are often sold via late-night infomercials, at prices ranging from $20 to over $100 each.

The US EPA is required to test many of these devices under Section 511 of the Motor Vehicle Information and Cost Savings Act, and to provide public reports on their efficacy. Most devices on the market are not found to improve fuel efficiency to any statistically measurable extent.

Many other reputable organizations such as the AAA and Consumer Reports have performed studies that have found similar results.


Urban legend

There is a related urban legend about an inventor who creates a 100 mpg (2.35L/100km) carburetor, but after demonstrating it for the major vehicle manufacturers, the inventor mysteriously disappears, in which he may have been killed by the government. The urban legend is thought to have started after Charles N. Pogue filed US Patent #1,750,354 for such a device. Though the legend has a basis in reality, it's unlikely that there has been a conspiracy to hide such an invention.