The term drag-limited refers to the top speed of an automobile that is affected more by the aerodynamics of the vehicle than the engine power.
When a vehicle's top speed is drag-limited, the engine does not reach its maximum power before the vehicle reaches its top speed. The aerodynamic design of the vehicle, therefore, limits its maximum speed.
The design of a vehicle affects the way air moves around it. Drag is increased by the amount of air that cannot move around the object and slows it down. The more air that hits an object, the greater the amount of drag.
In contrast to drag-limited vehicles, rev-limited vehicles are not limited by aerodynamics in reaching their top speed. Rev-limited vehicles reach their top speed at the maximum power of the engine, when they reach their highest amount of revs per minute.
