John Hennessey, the tuner of all things American, personally takes his tuned Jeep Gran Cherokee SRT8 down to the drag strip to test the car’s acceleration in a classic quarter mile run. The car boasts the HPE650 package which as the name suggests makes 650 horsepower.

As a result, this large 4×4 manages to run the quarter mile in 12.6 seconds @ 110 mph, hitting 60 mph on its way after just 3.9 seconds:

http://www.youtube.com/watch?v=Fm1Z3kz6bQU

The HPE650 treatment includes a complete overhaul of the Cherokee’s 470 horsepower HEMI engine. It adds new cylinder heads, custom air intakes and bespoke exhaust system, upgraded fuel injection and revised ECU software. On top of all this there is the TVS2300 supercharger.