One of the coolest things about John Hennessey, the boss of Texan tuning firm Hennessey Performance Engineering, is that he puts his money where his mouth is. He gets behind the wheel and demonstrates the performance his cars first hand. Here’s John doing a 0 to 60 mph test in the 2015 Hennessey GMC Yukon Denali.

This Hennessey GMC Yukon is equipped with the tuner’s HPE600 package, developing 605 bhp and 621 lb-ft Torque. The car is visibly uncomfortable dealing with all that power, but think how much fun it is challenging Ferraris and Porsche in this big SUV. HPE is also working on a 1,000 horsepower package for this engine.

Hennessey GMC Yukon Denali HPE600 package details:

• 2.9 Liter Supercharger System

• High Flow Intercooling System

• HPE Engine Management Calibration

• All Necessary Gaskets, Fluids & Hardware

• Professional Installation

• Dyno Tuning & Road Testing

• Serial-Numbered Dash Plaque

• Serial-Numbered Engine Plaque

• Hennessey Exterior Badging

• HPE600 Exterior Badging

• Supercharged Badging

• Hennessey Embroidered Headrests