Aerodynamics

(known vehicles)

CD = 0.347; CDA = 7.83 ft²; CLA = 3.38 ft²
Drag & lift coefficients
For each category, select the most appropriate choice for your vehicle. Use tooltips for more info. Drag coefficient is at the bottom of your screen.
Shape
Front - Plan:

Semi-circular
1

Well-rounded
2

Rounded corners I
3

Rounded corners II
4

Squared tapered-in
5

Squared constant width
6
Front - Elevation:

Low, rounded,
sloping up

1

High tapered
rounded bonnet

1

Low, squared,
sloping up

2

High tapered
squared bonnet

2

Med. height, rounded,
sloping up
3

Med. height,
squared, sloping up
4

High, rounded,
flat bonnet

4

High, squared,
flat bonnet

5
Scuttle & wing cross-section:

Flush,
well-rounded sides
1

High scuttle,
low wings
2

Flush,
rounded top wings
3

High scuttle,
rounded top wings
3

Flush,
squared-edge
4

Depressed,
squared-edge
5
Windscreen - Plan:

Full wrap-around
1

Wrapped round ends
2

Bowed
3

Flat
4
Windscreen - Peak:

Rounded
1

Squared
2

Forward-projecting
3
Canopy - Plan:

Tapering to rear
1

Constant width
2

Tapering to front
3
Rear canopy/boot:

Fastback
(θ = 10°-20°)
1

Semi-fastback
2

Squared canopy
& boot
3

Rounded canopy
& boot
4

Hatchback
(θ = 40°-90°)
4

Rounded canopy, no boot
5

Hatchback
(θ = 25°-35°)
6
Lower rear quarters:

Tapering to rear
1

Constant width
2

Outward taper
3
Underbody:
Skin friction:
Internal flow:
Openings:

Closed cockpit

0

1 open window
(race car)
3

1 open window
(prod. car)
5

Open cockpit
(race car)
6

Convertible,
pick-up
9


Shape CD: 0.26
*Drawings for Openings from Theory of ground vehicles, 2nd ed., J.Y. Wong, 1993, p. 183 (modified)
*All other drawings from Handbook of Vehicle Design Analysis, John Fenton, 1996, p. 336-337 (modified)

Wheels
Front





Tire:
Width/Diameter ratio: 0.327 (more)


CD: 0.045
Rear





Tire:
Width/Diameter ratio: 0.327 (more)


CD: 0.045


CD for all wheels: 0.09

Lift-induced drag
Lift F/R distribution




F/R dist.: 67/33










CL: 0.15
induced CD: 0.001
*Based on frontal area.


Complete CD: 0.347
Frontal area
Overall dimension
Width:
Height:
72.0 in
55.0 in
(more)



Frontal Area: 22.55 ft²

c o m p u t e d  b y :
HPWizard.com
Drag factor (CDA): 7.83 ft²
Lift factor (CLA): 3.38 ft²

Theory (more)