The 2015 Cadillac Escalade is one of largest and boxiest full-size SUVs->ke145 nowadays. I'm not saying it is not stylish, but that thing is huge, heavy and seemingly slow, but once its 420-horsepower V-8 comes to life, the Escalade is anything but slow. In fact, it takes only 6.4 seconds to charge from naught to 60 mph, which is faster than a Subaru BRZ or Scion FR-S, and it reaches the end of a quarter-mile strip in 14.8 seconds.

On the other hand, we know that some potential buyers would like the 2015 Escalade to be a tad quicker. This is where Hennessey Performance->ke1863 and its HPE550 package comes in. The upgrade places a supercharger atop the 6.2-liter V-8 and adds performance-enhancing parts, including a high-flow intercooling system. The result? Output goes up to a whopping 552 ponies and 565 pound-feet of torque, while it 0-to-60-mph drops to 4.9 seconds. Although the Texas-based company hasn't released quarter-mile figures yet, it's safe to assume the Escalade HPE550 is in the low 13-second range.

One thing's for sure, the supercharged Escalade is definitely faster than a base model, and the video above proves just that. Hit the play button to find out why Hennessey charges a $15,950 premium to tweak the 2015 Escalade.

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