Air Drag Coefficients and Frontal Area Calculation:

The use of coefficient of drag and frontal area are common when determining horsepower requirements for vehicles in motion. One source of these figures are past issues of Car and Driver or Road and Track magazines. 

Coefficient of Drag:
The aerodynamic "features" of a vehicle in motion are reflected in its drag coeficient values. Low coefficients indicate low air resistance. The following chart list some ranges for various vehicles, which will suffice when actual measured values are not available: 

     Vehicle		Drag Coefficient
     Type       	Low     	Medium   High
     ----------------------------------------------------------
     Experimental      	0.17    	0.21     	0.23
     Sports            	0.27    	0.31     	0.38
     Performance       	0.32    	0.34     	0.38
     60's Muscle       	0.38    	0.44     	0.50
     Sedan             	0.34   	0.39     	0.50
     Truck             	0.60   	0.90     	1.00


Calculation of Frontal Area
Frontal area represents the front projection area of the vehicle. If one takes a picture of a vehicle, it is the area included in the outline. Use the following to calculate: 

1. Calculate the area of a rectangle which would encompass the front of the vehicle (multiply width by the height, both in inches). 

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Drag coefficients compiled by Bruce Bowling
