Imagine the look on the face of a Porsche owner that just laid down almost $90K for a new Cayenne Turbo when he gets smoked by a Jeep Grand Cherokee SRT-8. That vision can be a reality thanks to the 420-horsepower, 6.1-liter Hemi V8 residing under the hood of the 2006 Jeep Grand Cherokee SRT-8. Thanks to its 420 lb.-ft. of torque, the Grand Cherokee SRT-8 hits 60 mph in under five seconds.