Aerodynamics what? Hennessey likes strapping Christmas trees to cars and then seeing how fast they’ll go. Awesome, it makes for some great entertainment. The tuner company used a Dodge Challenger Hellcat Widebody for its first run a couple years ago, but this time it’s used a Jeep. Specifically, it’s a 1,012-horsepower Hennessey-fettled Grand Cherokee Trackhawk. The goal was to beat the Hellcat’s run of 174 mph.
The test took place at the Continental Tire Proving Grounds in Uvalde, Texas. Hennessey says the tree was a six-foot Douglas fir it bought from Lowes. The tree even has lights on it this time, but it’s hard to tell as it zooms by at extra-legal speeds. This particular Jeep, the HPE1000 Supercharged Upgrade, is one customers can actually buy from Hennessey. It brings the 707-horsepower Jeep up to 1,012 horsepower and 969 pound-feet of torque. That’s good for 0-60 mph in 2.6 seconds and the quarter-mile in 10.2 seconds, according to Hennessey. So yes, it’s stonking fast.
Hennessey doesn’t release a top speed for the modified Jeep (it's capable of 180 mph stock) without the tree, but it manages 181 mph with the fir strapped to the top. Surprisingly, the tree stays mostly intact at those speeds. We’re not seeing mass needle loss or any branches mysteriously disappearing. The ornaments hanging from the mirror are a nice touch to get in the Christmas spirit, as well. Next time somebody tells you to slow down with the Christmas tree on the roof, just show them this video. Assuming it’s properly tied down and healthy, your Douglas fir can handle 181 mph. Just make sure you head to your nearest proving grounds to begin testing this Christmas Eve.