by Sam Abuelsamid on Mar 16th 2009 at 11:58AM In many ways, the Jeep Grand Cherokee is one of the best vehicles in Chrysler's lineup. Along with the Wrangler, it packs real off-road capabilities into an angular, no-nonsense body. It's an authentic Jeep, first and foremost, and makes no excuses for being anything another than a full-fledged SUV. Then there's the SRT8 version. This is what happens when you let the hot-rod mavens at SRT play with time-honored Jeep tradition. Over the last decade, many manufacturers have created high performance SUVs and crossovers, but this beastie is the only one available with a HEMI. The SRT8 is the twisted offspring of the unnatural pairing of a Jeep and a Dodge Viper, and Chrysler was kind enough to loan us its hottest GC for a winter trip to the ski mounds of Northern Michigan. Find out how it behaved after the jump. The Jeep SRT8 gets visual and functional enhancements inside and out, turning this off-road animal into a true street performance machine. As soon as you lay eyes on the SRT8, it's clear this is no directionless Compass. The body sits one inch closer to the ground with 20-inch forged aluminum wheels at each corner, wrapped in Goodyear Eagle RS-A tires with 255s in front and 285s at the back. Inside those massive hoops are four-pot Brembo calipers grabbing 14.1-inch front- and 13.8 rear rotors, all vented for better cooling. As one would expect of an SRT model, a deep front air dam, rocker panel extensions and rear bumper cover make the Jeep look even closer to the ground. Anyone trying to follow the SRT8 down the road will see a pair of four-inch exhaust pipes that exit from the center of the rear fascia, and those within earshot will here a wonderful bellow from that big V8. Like its SRT8 brethren built on the LX platform, the Grand Cherokee SRT8 gets a heart transplant thanks to the high-output, 6.1-liter HEMI V8. The important number with the HEMI is 420, as in 420 horsepower and 420 lb-ft of torque. This is a classic American muscle-car engine with a throaty growl and gobs of torque anywhere in the rev-range. It's not especially sophisticated by modern standards, with a single cam-shaft sitting in the valley of an iron block. No turbos, no superchargers, not even direct injection – but that's okay. Like the small-block V8 that still serves General Motors' performance products so well, this is a highly developed engine that simply works. Compared to the regular 5.7-liter HEMI, this boasts larger displacement along with a higher compression ratio and redesigned cylinder heads with better flow in and out. The SRT8's considerable twist goes through a beefed-up torque converter to a five-speed automatic transmission and on to all four wheels. While competitors like the Infiniti FX50, Porsche Cayenne and BMW X6 get six- or seven-speed gearboxes, the reality is the Jeep doesn't really need the extra gears. There's plenty of torque no matter where you dip into the throttle and drivers will never be left wanting for acceleration. The shift lever features Chrysler's Auto-Stick left-right tap shift, but it really isn't needed. Stepping on the go-pedal brings downshifts quickly and maximum velocity on demand. When the original Grand Cherokee debuted in the early '90s, it had surprisingly good dynamic capabilities, particularly when you realize those first-gen. models were fitted with live axles at both ends. Today's modern model comes equipped with an independent front suspension, and it still has some of the best ride and handling characteristics of any SUV. Even rolling on 20-inch wheels, the SRT8 isn't punishing on Michigan roads and nobody was complaining when they climbed out at the ski resort after a long stint on the road. With as much torque and rubber as the Grand Cherokee SRT8 has, it's even more important for the driver to stay planted in front of the steering wheel. To that end, Chrysler has equipped this Jeep with the same amazing front seats found in other SRT models. The side bolsters are large and firm, and those sitting on the driver's side can adjust the throne to fit different torso widths. The front seats are power adjustable and the driver's seat can automatically slide back when the door opens to ease entry and exit. That's a surprisingly welcome feature given those large bolsters and the angle of the thick A-pillar. Without the automatic retracting seat, it would be easy to hit your head getting in and out. The A-pillars have built-in grab handles on both the driver and passenger side, and their girth can be a bit of a problem, creating large blind spots at the front corners. The only other ergonomic complaint we had is the narrow gap between the doors and seats. If the adjustments were mounted on the door or center console this wouldn't be a problem, but since they're down on the side, they can be difficult to reach. The layout of the interior is generally good, with controls within easy reach and even power adjustable pedals. Most of the dash is still covered in hard plastic, but the finish is better than most of Chrysler's past (and current) offerings. The back seat has plenty of room, enough to satisfy two teenagers who never complained about being crowded in either leg or head room, even though our tester was equipped with the optional sun-roof. The SRT8 was also fitted with the optional rear seat entertainment system with ceiling-mounted DVD screen and wireless headphones, allowing the kids to entertain themselves on the four-hour drive. The instrument cluster has the usual driver information panel found on a host of other vehicles, although the SRT8 adds performance meters to the usual trip odometer and mileage displays. The driver can select a longitudinal and lateral accelerometer display or several different acceleration timers including 0-60, 60-0, 1/8 mile and 1/4 mile. Chrysler claims sub-five second 0-60 acceleration and 60-0 stopping of 125 feet, and this Jeep consistently lived up to those claims (with a margin for error) even with a second independent measuring device. When the time does come to reduce speeds or deal with roads that are less than freeway straight, all the hardware upgrades on the SRT8 really pay off. One of the beauties of Brembo's brake calipers is the stiffness under pressure. Lesser calipers will flex when the brakes are applied hard giving a soft spongy feel to the pedal. Not so in the SRT8, where the pedal always feels firm and the amount deceleration seems directly proportional to the pressure applied to the pedal. Speaking of proportionality, there is even some degree of feedback in the thick rimmed steering wheel as the Cherokee moves through curves. It's no Lotus or even a BMW, but for a Jeep it's a pleasant surprise. Since the SRT8 is an SUV, some degree of utility is expected and this one lived up to its middle name. The Grand Cherokee handily beats the aforementioned competitors with 34.5 cu-ft of luggage space, plenty of room for four suitcases, four pairs of ski boots, and assorted other flotsam and jetsam. The massive subwoofer that comes as part of the optional Kicker audio package does eat up a chunk of space, so if you need to maximize volume, you might want to pass on that. The 2009 Grand Cherokee SRT8 proved to be quite a fun ride and a pretty decent road-trip machine. Its interior isn't up to the same standards as those Japanese and German performance SUV/CUVs, but it's certainly more than livable. Compared to its competitors, the Jeep is also quite a bargain. Our heavily optioned unit came to $50,760 – which certainly isn't cheap – but it's half the price of a Cayenne Turbo before you begin ticking off the options. Given the Jeep's thirst for gasoline, the price difference will take you a long way, and we would be surprised if there aren't dealer discounts to be had, too. The EPA rates the SRT8 at 11 miles-per-gallon city and 14 highway. Over our 450 miles of mostly highway driving, we got 15.1 mpg, but aggressive driving will very easily drive that number down quickly. However, if you're looking for a fast SUV that doesn't sacrifice utility and doesn't need to go off-road, the SRT8 is definitely worth a look.