It's the answer to a question only Hennessey Performance Engineering would ask: How fast will a Christmas tree go when strapped to the roof of a Dodge Challenger Hellcat wide-body? You know, for those times when a last-minute Christmas tree is imperative. 

HPE ran a bone-stock Challenger Hellcat wide-body equipped with a roof rack to get a baseline top speed. The final figure was 177 mph. Adding a Christmas tree will certainly hurt aerodynamics, and it did, but not by much. After strapping the Christmas tree to the roof, Hennessey's driver set out for another top-speed run at full throttle. Once the raucous muscle car shifted into its final gear, the speedometer slowly crept past the 170 mph mark and seemed stuck around 171 mph. But the Challenger Hellcat, replete with Christmas tree, didn't give up so easily.

As the road began to run out, the speedometer finally clipped 174 mph, which made this the fastest Christmas tree we've ever seen.

Sharp eyes will notice that the Hellcat's fuel gauge slowly, but surely, slipped past the "Full" mark as the driver ran the car flat out. The 6.2-liter supercharged Hemi V-8 is a thirsty thing. 

In typical HPE fashion, the whole shebang ends with a smokey burnout because, well, why not? Check out the holiday-themed top-speed run in the video above.