That power comes courtesy of an all-new 6.4-liter HEMI V8 that builds on the outgoing 6.1-liter model by offering an additional 45 horsepower and 45 lb-ft. of torque. Chrysler says that its engineers worked especially hard to make 90 percent of the engine's peak torque available between 2,800 and 6,000 rpm.
To reduce fuel consumption, an active valve exhaust system cuts out four cylinders, which Jeep says helps increase fuel economy by 13 percent on the highway. Combined with a large gas tank, Jeep says the Grand Cherokee SRT8 should be capable of a 450 mile range.
Inside, the Grand Cherokee SRT8 gains steering wheel-mounted paddle shifters to control the five-speed automatic transmission.
Jeep says it worked hard to further refine the Grand Cherokee SRT8?s handling by building on the all-new WK2 platform with a new Selec-Track traction-enhancing system. With a name that conjures up images of Jeep's SelecTrac transfer case, the new Selec-Track interacts with the stability control, adaptive damping, transmission shift strategy, transfer case torque proportioning, electronic limited slip differential, throttle control and cylinder de-activation. Five modes ? Auto, Sport, Tow, Track and Snow ? ensure ideal traction for any situation. Unlike the previous Grand Cherokee SRT8, the new SUV is designed to be used year round for a variety of uses ? even towing.
A single-speed transfer case sends power between the front and rear wheels. Uprated power steering and Brembo six-piston front and four-piston rear brakes help the Grand Cherokee maintain control. Jeep says that the new SUV will stop from 60 mph in just 112 feet.
The 2012 Grand Cherokee SRT8 is more aggressive looking than before with exclusive front and rear fascias with LED daytime running lamps and chrome bezel inserts completing the look.
A new rear liftgate spoiler is designed to reduce drag and improve downforce at high speeds.
Riding on split five-spoke 20-inch alloy wheels, the Grand Cherokee SRT8 will be available with either all-season or three-season Pirelli P-Zero runflat tires.
Inside, the SRT team upgraded the Grand Cherokee's interior with a three-spoke steering wheel with a flat bottom, Nappa leather and suede seats and extensive carbon fiber accents. SRT's Performance Pages trip computer functions remain, meaning the Grand Cherokee SRT8 can display performance figures like 0-60 time, 60-0 distance, g-forces and one eighth and quarter mile times.
In addition, a new 825-watt 19-speaker audio system boasts a 10-inch subwoofer
Competitors: BMW X5 M, BMW X6 M, Porsche Cayenne Turbo
Powertrain: 6.4-liter V8, 470 hp, 470 lb-ft; five-speed auto, AWD
EPA Fuel Economy (city/highway): 12/18 estimated
What's New: The all-new 2011 Grand Cherokee helped fuel Chrysler's renaissance. In little more than a year, the company has transformed most every model, including the popular Jeep. The sporty and luxurious SRT8 edition builds on the modern chassis of the 2011 WK2 (Jeep code for the second-generation Grand Cherokee). That chassis actually began its development life with the also-all-new 2012 Mercedes M-Class SUV. Major advances since the previous SRT8 Grand Cherokee include hugely improved torsional stiffness (146 percent better), a larger hemispherical combustion chambered engine (6.4 liters versus 6.1), more power (470 hp versus 420 hp), huge Brembo brakes with 6-piston front calipers, paddle shifters and a two-mode adjustable suspension. Unlike the first-generation SRT8 Grand Cherokee that couldn't tow anything, the second-gen model is equipped to tow up to 5000 pounds.
Tech Tidbit: Jeep and four-wheel drive are nearly synonymous. Not surprisingly, the GC SRT8 features a high-performance driveline that permanently powers all four wheels. This is unusual among SRT products. The five-mode Selec-Track system adjusts engine power delivery, transmission shift points, transfer case torque splits, suspension damping and the locking rear differential to create distinct driving characteristics. Modes include Auto, Sport, Track, Snow and Tow.
Driving Character: The Grand Cherokee SRT8 makes its personality known from the moment you fire the 470-hp Hemi. The exhaust's quiet cadence reminds you of the SUV's mid-4-second 0?60 mph potential. Pulling away from a rest, the weighty hydraulic rack-and-pinion steering requires some arm strength but rewards the fingertips with great feedback. The Selec-Track "Auto" setting masks small pavement imperfections such as tar strips, making everyday driving duties quite livable. Spinning the big knob to Track amplifies the GC's senses like a syringe of adrenaline. During our recent test, the 5150-pound SUV took to the high-speed Willow Springs Raceway like Secretariat to Churchill Downs. Thankfully, the always-active all-wheel drive and sticky 20-inch Pirelli tires imbue fun but forgiving handling dynamics.
The Bottom Line: Unlike any other Jeep, the Grand Cherokee SRT8 isn't designed for the Rubicon Trail. Massaged by Chrysler's in-house skunk works, the Street and Racing Technology group, the Grand Cherokee SRT8 epitomizes an innovative product that nobody knew they wanted?a Jeep allergic to rocks and gravel. The exterior dramatically alters the standard GC's attitude from mountain man to urbane superhero. Everything is functional, including the hood vents that exhaust power-robbing hot air trapped in the engine compartment. The heavily bolstered bucket seats help carryover the SUV's attitude adjustment to the interior. The speedometer shows 180-mph worth of hash marks, and the Jeep can hit at least 160. The adjustable nature and resulting smooth ride from the Selec-Track system lends the GC SRT8 every-day potential, provided its thirsty consumption (12 mpg city, 18 mpg highway) isn't a deal breaker. Drivers shopping for a BMW X5 M, X6 M, or Porsche Cayenne Turbo may not consider the 2012 Jeep Grand Cherokee SRT8. But that would be their loss.