[kach22i]

The “large wind tunnel” in Untertürkheim | Mercedes-Benz Passion eBlog


http://www.autospeed.com/cms/article.html?&A=112241

It was mentioned above that underfloor drag is responsible for about one-third of the total drag of a current car. The other proportions are also easy to remember – about one-third for all the exterior surfaces and the last third caused by airflow required for engine cooling. (See Modifying Under-Car Airflow, Part 1.)