This is where the drag coefficient — which measures how well a vehicle cuts through the surrounding air — comes into play. For this benchmark, lower numbers indicate less wind resistance.

This slows the object down. Resistance in air and water is a type of frictional force that is also known as drag. Objects with a large surface area can produce more drag. The faster an object ...

but one of the latest developments is a prototype called the Airshield—which is pretty much what it sounds like—a drag-reduction device that allows athletes to run without air resistance.