Ever since the first Oldsmobile rolled off the production line in 1901, drivers have been hell-bent on improving everything from fuel efficiency to braking systems. That quest for building a better whatever always leads to stories about bizarre tonics and applications that increase power, improve gas mileage or somehow give your car super powers.
One of the most popular automotive claims of the past couple decades is the rumor that adding acetone to your gas tank can increase your car's gas mileage efficiency. Although this urban legend has repeatedly been debunked, it still seems to surface every few years. The Claim
The false premise is that acetone creates an explosive factor on the surface of drops of gasoline. The acetone allegedly makes the gas evaporate more quickly, creating a higher density before the gas goes into the cylinder to ignite the spark plugs. Thus, creating a gas mileage improvement of 25 to 30 percent.
Proponents of the theory conveniently ignore the fact that the gas is already a scorching 400+ degrees traveling at a speed of 250 mph without the acetone, factors that would already transform the gas into steam. Since the amount of fuel that doesn't burn when it's in the pre-catalytic converter is calculated in parts per million, the result of adding acetone would be negligible. The Reality
Despite the ardent claims of many mechanics and motorists, testing and trials by automotive and fuel experts have repeatedly failed to indicate any notable change in gas mileage when acetone is added to gasoline.
When the enthusiasts insist their independent tests have indeed indicated measurable increases in gas mileage, professionals are quick to rebut their claims. Since the experiments by laypersons are not conducted in a controlled environment, professionals claim such results are tainted by slipshod calculations and measurements, rendering the tests inconsequential, as they have never been able to be replicated in a laboratory. The Possible Consequences
If adding acetone to gasoline tanks was benign, it would probably be readily dismissed as pointless and harmless; however, that's not the case. There are serious consequences to adding a corrosive solution that easily removes nail polish and paint from surfaces to a liquid that fuels your car and travels through an intricate combustion system. The idea of increasing gas efficiency with a known solvent is highly questionable, at best. Realizing that the acidic solution dissolves rubber engine parts like gaskets and O-rings, as well as fuel lines made of rubber, should be a HUGE red flag for supporters of adding acetone.
Aside from the way acetone destroys rubber, it also ruins the finish of your car if you only spill a drop when you're adding it to your gas tank. A telltale sign of an acetone supporter is a line of missing paint right under the gasoline receptor on a vehicle.
In addition to the acetone myth, there are gadgets that claim they will improve gas mileage with fans and other paraphernalia. The only reliable way to get better gas mileage is to buy a car that's factory-equipped with various features that burn less gas because of technology and/or changing your driving habits.