Man, it sure feels like the holidays always arrive quicker than the year before, and it appears Hennessey enjoys helping. The Texas-based tuner and builder has a tradition of strapping a Christmas tree to the top of something powerful to see how fast it can go, and this year, Hennessey strapped the tree to the roof of a tuned Porsche 911 Turbo S. However, it’s not just any Porsche, it’s John Hennessey’s personal machine.

Details about the tuned Turbo S are elusive, though we know it makes 750 horsepower (559 kilowatts), which is a nice step up from the stock 641 hp (477 kW). It’s plenty of power for the coupe to reach a staggering 175 miles per hour (281 kilometers per hour) with the tree strapped to the roof. It’s impressive, though far below the car’s actual top speed. A second run around the tuner’s Pennzoil proving ground without the tree strapped to the roof reaches 206 mph (331 kph). That’s a 30-mph difference.

Gallery: Hennessey Porsche 911 Turbo S With Christmas Tree On Roof

Racing driver Spencer Geswein piloted the Porsche, and in the video, you can hear him say that removing the tree made the car feel entirely different. Removing the aerodynamically unfriendly tree reduced the car’s drag significantly and changed how the car handled at speed, which isn’t surprising. Something that large on the roof at those speeds will tremendously affect how a car operates and feels to the driver.

The Porsche’s 175-mph top-speed run is fun to watch, but it is not Hennessey’s fastest Christmas tree ever. That title goes to the Hennessey-tuned Jeep Grand Cherokee Trackhawk, which used all 1,000 horsepower to hit 181 mph (291 kph), the SUV’s actual top speed. The extra drag for the beefy, flat-nosed SUV didn’t deter it one bit, with the extra oomph from the Jeep’s tuned Hellcat V8 easily overcame the tree’s drag.

Got a tip for us? Email: