Buying a car that has had some aerodynamic testing is a smart idea. On the other side of the coin a car with a horrible drag coefficient will get horrible gas mileage!
We all know what drag coefficient is right? Well ok maybe only the geeks and nerds out there know about drag coefficient. According to Wikipedia: “Drag Coefficient is used to quantify the resistance of an object in a fluid environment such as water or air.” The lower the drag coefficient the more aerodynamic the object is. Why is this important, because the shape of your car directly affects its gas mileage? If you are going to make a fuel efficient car then something like drag coefficient must top your list. Minimizing drag will help fuel economy at the greater speed you go. Drag will not have much effect on a 20-30 mph drive, but speed up to 80 MPH and wind resistance is a larger factor in you miles per gallon.
The mass marketed car with the best drag coefficient at 0.25 is the 1999 Honda Insight…you know the ugly little car
with the rear wheels covered. Well the guys at Honda were willing to sacrifice looks for fuel economy. And this car was estimated to get 71 MPG on the highways! Well now the 2010 Toyota Prius will tie that mark!
High performance cars also pay attention to drag coefficient as this will affect their top speeds. The Corvette, Lamborghini, Lotus, and Porsche all have drag coefficients in the 0.28 - 0.31 range. But by far the worst automobile for in term of drag coeffiency is the Hummer H2 at 0.57!
So there you have it the better the drag coefficient the better your MPG will be. This is why hybrid cars like the Prius and Insight also get the best gas mileage. The low drag coefficient is as much a testament to fuel savings as the hybrid power plant.
Source: Wikipedia
