Reply #96: Drag on cars

[VTMechEngr]

A large portion of the drag is caused when the flow separates from the car body at the rear and fills the lower pressure area caused by the car displacing the fluid. This is why cars have narrow rears, with the trunk necking down and inward in many models, as this leaves as small of a low pressure region as possible when the fluid separates from the car body. Drafting very close in racing reduces the low pressure area, hence reducing the drag on the car in front and the on the following car.

On a truck, the effect would be hardly noticeable. The seperation area is too big to be negated by a car following, and the gain for the car will not impact the truck.

To put in in real simple terms, he's your blocker, and he takes the brunt of punching through the defenders whether or not you follow him into the end zone.


On edit: Trunk, not truck