Cheating Wind - Aerodynamic Tech and Buyers Guide

Cars Are Such a Drag

Some examples of drag coefficient found in the automobile industry throughout history and a few other objects for comparison.

2.10 - A smooth brick
0.90 - A typical bicycle plus cyclist
0.70 - A Formula 1 car
0.70 - Caterham Seven
0.60 - A typical truck
0.57 - Hummer H2, 2003
0.51 - Citron 2CV
0.42 - Lamborghini Countach, 1974
0.39 - Dodge Durango, 2004
0.38 - Volkswagen Beetle
0.38 - Mazda Miata, 1989
0.372 - Ferrari F50, 1996
0.36 - Citron DS, 1955
0.36 - Ferrari Testarossa, 1986
0.36 - Opel GT, 1969
0.36 - Citron CX, 1974
0.34 - Ford Sierra, 1982
0.34 - Ferrari F40, 1987
0.34 - Chevrolet Caprice, 1996
0.338 - Chevrolet Camaro, 1995
0.33 - Dodge Charger, 2006
0.33 - Audi A3, 2006
0.33 - Subaru Impreza WRX STi, 2004
0.32 - Toyota Celica, 2005
0.31 - Citron GSA, 1980
0.30 - Saab 92, 1947
0.30 - Audi 100, 1983
0.30 - Porsche 996, 1997
0.29 - Honda CRX HF 1988
0.29 - Subaru XT, 1985
0.29 - BMW 8 Series, 1989
0.29 - Porsche Boxster, 2005
0.29 - Chevrolet Corvette, 2005
0.29 - Honda Accord Hybrid, 2005
0.29 - Lotus Elite, 1958
0.28 - Toyota Camry and sister model Lexus ES, 2005
0.28 - Porsche 997, 2004
0.28 - Saab 9-3, 2003
0.27 - Rupler's Tropfenauto, 1921
0.27 - Infiniti G35, 2002 (0.26 with "aero package")
0.27 - Mercedes-Benz W203 C-Class Sedan, 2001 - 2007
0.26 - Toyota Prius, 2004
0.25 - Honda Insight, 1999
0.212 - Tatra T77, 1938
0.195 - General Motors EV1, 1996
0.19 - Mercedes-Benz "Bionic Car" Concept, 2005
0.137 - Ford Probe V prototype, 1985
0.15 - Volkswagen ARVW
0.06 - The boxfish
0.04 - A drop of water

To Change or Not to Change

When you modify your car in any way, you are changing the original design and the vehicle's overall characteristics. Sometimes that is a good thing, while other times it can lead to negative results. Below is a list of common modifications and their estimated change in percentage of the overall drag coefficient (Cd) of an average car. For example, the outside rearview mirrors add a two to four percent increase in the Cd. However, it should be noted that your results may vary.

Modification % Change
Lowering the vehicleby 30mm approx. -5
Smooth wheel covers -1 to -3
Wide tires +2 to +4
Windows flush with exterior approx. -1
Sealing body gaps -2 to -5
Underbody panels -1 to -7
Concealed headlamps +3 to +10
Outside rearview mirrors +2 to +5
Airflow into the enginecompartment +4 to +14
Brake cooling devices +2 to +5
Interior ventilation approx. +1
Open windows approx. +5
Open sunroof approx. +2
Roof-mounted surfboard rack approx. +40



Aerodynamics Buyers Guide

The Wind Beneath Our Wings
The latest and greatest in aerodynamics from the world's best design houses

Conversations and theories about aerodynamics abound in the automotive industry, and if you wanted to throw puns around, you could say it is a lot of hot air passing over stiff resistance. Does a car go fast enough to warrant a full body kit? Is a spoiler or airdam necessary on American highways? Will I affect my car's performance enough to offset the cost of the variety of packages on the market today? These questions can be argued until your car becomes an antique, but the only solid answer with any kernel of truth that everyone can agree on is that most aerodynamic-themed accessories make your car look cool. Whether they improve handling, fuel economy, or 60-foot times are issues best left to physicists, engineers, and bench racers (unless, of course, you have the time slips to prove it).
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0.28 - Toyota Camry and sister model Lexus ES, 2005. These boxes flow better than most Ferrari's probably because closes shaped to the last one, drop of water