The myths and misconceptions surrounding automobiles are as old as the automobile itself. Since the dawn of the modern era, people have believed in wild claims centered around various facets of the auto industry. Some of the stranger beliefs include the idea that red cars are inherently more expensive to insure, that all SUVs excel off-road, that ABS always shortens braking distances, and the genuinely outlandish notion that seatbelts are unnecessary in cars equipped with airbags.

While we could have a separate discussion on myths surrounding pickup trucks, one of the most popular beliefs centered around them is the notion that leaving the tailgate down on mean machines (like the Chevrolet Silverado 2500 HD Duramax and the GMC Sierra 1500 Denali) would actually cause them to burn less fuel. Apparently, this belief stemmed from the fact that leaving the tailgate down would cause the air to flow freely around the truck, but is that really the case?

As it turns out, this longstanding myth was comprehensively busted nearly two decades ago in a Mythbusters episode that aired on the Discovery Channel. They conducted a detailed experiment in which it was conclusively proved that leaving the tailgate down would, in fact, have the opposite effect and make the truck consume more fuel.