Saturday Drive: 2012 Jeep Grand Cherokee SRT8 The car: 2012 Jeep Grand Cherokee SRT8 4X4 The power: 470 horsepower and 465 pound-feet of torque from a 6.4-liter Hemi V-8 The photos: 2012 Jeep Grand Cherokee SRT8 4X4 The speed: 0-60 mph in 4.8 seconds The bragging rights: The fastest Jeep yet. The price: Base price is $55,295 including destination. As tested: $63,975. The details: Yes, this thing's got a Hemi. Chrysler Group's performance division, SRT (for Street and Racing Technology) has dropped its latest creation, a 6.4-liter V-8, into a Jeep, giving us the second Grand Cherokee SRT8. It puts out 50 more horsepower and 45 more torques than the previous generation 6.1-liter engine. In an effort to leave a little crude oil for the next generation, the engine is designed with cylinder deactivation. This allows it to run on four cylinders during highway cruising and helps the SRT8 hit an EPA-estimated 12 miles per gallon in the city and 18 mpg on the highway. During nearly 200 miles of testing, I averaged 10.5 mpg. More on why in a minute. Mated to this engine is an aging five-speed automatic transmission with paddle shifters. Meanwhile, electronic goodies like the four-wheel-drive transfer case and the limited slip differential put the power to the wheels. Jeep's Selec-Track system lets drivers choose one of five settings that vary the stability control, Bilstein adaptive suspension, shift mapping, torque split, throttle input and cylinder deactivation. Auto and sport are best for daily driving, with track ready for when you really want performance over comfort, and tow and snow each being self-explanatory. All these systems are wrapped in a Jeep Grand Cherokee body after a Gold's Gym treatment. The SRT8 sits an inch lower; the fenders are flared; the front and rear bumpers are completely redesigned and unique to this model; and the deep scalloped hood features two functional air scoops. An added bonus over the previous SRT8 is that the dual exhaust pipes are no longer center-mounted, meaning that you can tow 5,000 pounds if you add the $995 tow package my tester had. Five-spoke 20-inch rims, wrapped around four-wheel Brembo anti-lock brakes, round out the look. Inside, standard heated and cooled leather front seats feature suede inserts and extra-thick bolstering. Even thicker is the heated, flat-bottomed steering wheel. Genuine carbon-fiber trim is also standard, as is a media center with navigation system, heated rear seats, Xenon headlights and dual-zone climate control. My tester added the $4,495 Luxury Group, which includes additional leather trim throughout the cabin (like the dashboard), a power tailgate, blind-spot monitoring and adaptive cruise control. An additional $1,195 gets you a panoramic moon roof, while $1,995 throws in a 19-speaker audio system with a 895-watt amp. The drive: Let's be honest. A two-ton, 470-horsepower SUV that will go from standing to 60 mph in under five seconds while getting worse gas mileage than a Hummer towing New Jersey is silly. Unnecessary, excessive, illogical. I loved it. This is the kind of vehicle that would make John DeLorean and his cohorts at GM proud, they who stuffed a V-8 the size of a cruise ship into an engine bay where it didn't belong. But rather than a Pontiac Tempest, the good folks at Chrysler's SRT division started with an excellent vehicle that already has plenty of functionality. The rock-solid chassis of the Grand Cherokee provides an stout canvas on which to paint some SRT power. Thus, you get a vehicle with off-road fortitude of the more sane Grand Cherokees, the stiffness and road manners of a Mercedes ML (the two share a platform) and the surly aggression of a WWE wrestler who missed dinner. When driven briskly, this Grand Cherokee can do everything a Porsche Cayenne Turbo, BMW X5 M or Mercedes-Benz ML63 AMG is capable of, but without the oppressive glibness that comes with their six-figure price tags. Those vehicles say, "My driver could have more fun than you, if he or she ever wanted to," while this Jeep says, "Screw it, my driver IS having more fun than you." For $50,000 less. Put the SRT8 into sport or track mode and stomp on the gas and this sonorous V-8 rockets you forward with dizzying immediacy. I've driven plenty of cars that will wallop this Grand Cherokee SRT8's 0-60 mph time, but few make the experience so engaging. The Hemi V-8's sound is a refined, air-filled roar; it's never sharp or caustic. This absolutely is why I averaged 10.5 mpg in my week with the car. Launching from stop signs or green lights with this Hemi pulling your sled is just too much fun not to do repeatedly. When you've had your fill, the Brembo brakes end the party immediately. My only complaint about the driving experience was the numbness of the hydraulic steering. When chucking something this big and powerful through turns at speeds that laugh in the face of physics, you want to feel as much communication from the road as possible. With this Jeep you just have to learn to trust it. I'd also like a transmission with an additional gear, though this shortcoming stood out more on paper than it did while actually driving the vehicle. All told, the Jeep Grand Cherokee SRT8 is a phenomenal daily driver, and if it's my scratch on the counter, this is one of the best ways to spend $60,000 on a new vehicle today. You get the functionality, comfort and luxury of Jeep's most premium offerings paired with the unholy, yet civilized power from some of the brightest nerds in Detroit. Not wanting one is what is truly silly.