That is one fast Christmas tree.
During the holiday season, we all see cars driving around with big Christmas trees strapped to their roofs. It’s a common sight and we don’t put much thought into it, but how much drag does a tree add when driving? To answer this question, Hennessey Performance strapped a Christmas tree to the roof of a 750 horsepower Porsche 911 Turbo S to see just how fast it could go. During their test runs, the German sports car managed to hit a top speed of 175 mph with the added aero component. After this top speed run, the team removed the tree to see just how big of a difference it made. The driver, Spencer Geswein, reached a top speed of 206 mph. That’s a difference of 31 mph. So let this be a lesson: don’t go to the track with a Christmas tree strapped to your roof. But did we really need to say that?
Source: Hennessey Performance