2006 Jeep Grand Cherokee Review

The Worlds Quickest SUV?

Talk all you want about BMWs X5 4.8si, Mercedes-Benzs ML55 AMG, Porsches Cayenne Turbo, Volkswagen Touareg V12, or the all-new Land Rover Sport Supercharged, because the only one that would be left standing after a head-to-head acceleration duel would be one not yet mentioned, the relatively low-priced Jeep Grand Cherokee SRT8.

Am I serious? An SUV best known for scaling the Rubicon Trail can slay the best of the crossover utes on the track? Its true, and in some cases by a long shot. Take the new fully-blown 390-horsepower Land Rover Sport, which after dropping $69,085 can only managed 60 mph in 7.8 seconds. What about Mercedes mighty ML55? Well, M-B hasnt massaged the all-new model with an AMG upgrade yet, but the old one managed the 60 mph feat in only 6.2 seconds while the new ML500 comes close to the mark with an impressive 6.7 seconds. BMWs X5 4.8si manages a rather impressive 6.0 seconds to 60, while Volkswagens seemingly omnipotent 450-horsepower Touareg W12 overcomes 60 mph in only 5.8 seconds - how stimulating despite not being available in North America. And what about Porsches turbocharged variant? The Cayenne sweeps past the marker in, whoa, a stunning 5.3 seconds when the Tequipment package is added on, upping the price to $109,200. But wait a minute? News just in (at least at time of writing), a new $111,600 Cayenne Turbo S, just introduced at the Greater Los Angeles Auto Show sees 60 mph in 4.8 seconds… no doubt a direct response to being beaten by the comparably labor-class 420-horsepower Grand Cherokee SRT8 - which just happens to feature 90 additional horsepower, a 27 percent higher output level than the already potent 5.7-liter HEMI-equipped Jeep Grand Cherokee. Thats right, the domestic super-SUV manages the feat in “less than five seconds”; all Jeep is willing to admit. Up until the LA auto show, it was the clear winner by an estimated 0.4 seconds, which is a long shot in acceleration tests. Now, at least, the SRT8 has a worthy competitor, but at a price.

Fortunately for lovers of relatively inexpensive super-SUVs, the Grand Cherokee SRT8 starts at a mere $39,300. Of course, there arent many other relatively inexpensive hyper-powered SUVs to compare it to, other than Chevys 395-horsepower TrailBlazer SS at $31,800, which I have been told is surprisingly nimble but not as sporting as Jeeps latest entry, although its substantial discount might make take the edge off of losing out on the track. And such a sum is equal to at least a few years of premium unleaded (or more if you factor in interest rates over four or five years), and more if consider the SRT8s thirst for fuel. But those opting for the non-MDS equipped 6.1-liter variant probably wont be caring too much about such details, at least at first. What will matter more are the 420 ponies under the hood, complemented with 420 lb-ft of rubber burning torque.

At take-off its otherworldly. With the right foot planted solidly on the throttle it pins all occupants into the backs of their seats with a gravitational pull that must be reminiscent of a Cape Cod launch, although the resonant bass-like gurgling exhaust that immediately changes tune to a higher pitched roar made me feel as if I was actually inside “FrightMare”, the worlds largest Jeep, other than the lack of a roof, missing roll cage, the requisite fire extinguisher, and the fact that the Jeep handles curves at supercar speeds almost as well as it accelerates.

My driving partner and I started the climb out of Pasadena, California on a regular hot, sunny day, up over the Angeles Crest highway, easily one of the best roads the world has to offer driving enthusiasts and appreciators of scenic vistas alike, right onto the Angeles Forest Highway, also spectacular for both passions, and then on the Antelope Valley Freeway towards Palmdale and Lancaster, California, home to the Edwards Air Force Base as well as a desert haunt I once had to spend a little more than a week in at 110 to 120+ degrees, rebuilding my carburetor, repairing a rusted gas tank and still waiting for yet more Suzuki GS750 parts to arrive - another story, another time.

It wasnt as hot as we passed through town today, nor did it matter as the Grand Cherokee SRT8s air conditioning was pumping out cold air as we bided our time, cautiously making our way past Californias finest mounted on their cream-white H-Ds, looking about as authoritative as men in blue get. Little did they know that we just experienced one of the most entertaining roller coaster rides of our lives, and Im not talking Six Flags just down the Bouquet Canyon in Valencia, Knots Berry Farm in Buena Park, Orange County, or for that matter the good old Matterhorn bobsleds in Disneyland, in Anaheim.

The Angeles Crest highway is spectacular, and the Grand Cherokee SRT8 might just be the fastest way to get five of your friends and all of their gear to the top. The hyper-Jeeps handling is outrageous, slicing and dicing up corners quicker than my brother-in-law Tony can do in celery and carrots (hes a professional chef after all). What this thing (the SRT8) can accomplish, considering its rather porky and inherently top-heavy configuration, defies Newtons gravitational law, surprising me and my copilot, holding on for dear life while grinning like an eight year old with a new slot-car set.

It manages such feats of brilliance because of a great deal of massaging by the Street Racing Technology (SRT) teams expertise in tuning suspension systems. To start with, the chassis is upgraded with performance-tuned springs and dampers, up-rated bushings and thicker anti-roll bars, minimizing body roll and firming up the ride - but not so much that it punished driver or passengers in any way. New front suspension knuckles with added camber angle are also added, designed to help the SUVs W-rated Goodyear Eagle RS-A run-flat tires, measuring 255/45WR20 up front and 285/40WR20 in back, maintain optimal contact to the road. Additionally, the GC SRT8 has been lowered by about an inch, not only making it look better, combined with its racy new aerodynamic add-ons, but reducing its center of gravity while making it a little more slippery when pummeling the air. Jeeps engineers would have been not to have included stability control, for legal reasons alone, so therefore the GCs stock Bosch-sourced ESP (Electronic Stability Program) has been revised to allow greater driver input before cutting in to save the day.

Once at Willow Springs Raceway, after some course instruction and a little lunch, I hopped back into the Jeep so that my experience would be seamless, from the road to the track. Again, it didnt disappoint, but the SUVs inherited height and heft did become more apparent, due to the speeds attained, especially around the slightly off-camber Rabbits Ear corner, the second turn out of the pits, a 450-degree radius sweeping right that allows for tremendous speed if your right foot maintains a steady throttle.

Through turns three and four, overseen by the Budweiser Balcony, a really tricky assortment of steep uphill and then equally steep downhill sections that form a convoluted “U” shape atop one of the highest elevation changes Ive ever seen on a racetrack, the GC did well, as long as, once again, a steady throttle was applied amid short, purposeful braking when necessary. Coming down off of the hill, but still fairly high above the pits, the course turns sharply left through five, but if set up right its a really quick corner, and then, after a rollercoaster-like dip, up, over and just lightly to the right through turn six, otherwise known as Monroe Ridge. Again, the Grand Cherokee SRT8 performed flawlessly, feeling almost like it was in the air over the ridge, but no doubt maintaining four full contact patches just the same. This is good, because by the time I got down the Wings Leg stretch to the longest, most uniform turn of all, close to 130 mph had racked up on the speedometer, and, at least on the first few times around, I automatically applied some brakes to slow down and set up the 900-degree radius aptly named Sweeper, turn eight. Im glad I slowed down too, as turn 9, which is really just an extension of turn eight with a tighter 600-degree radius turn-in, snuck up on me quickly, and its off-camber configuration made it so I needed to use all of the ensuing track, which is fortunately quite wide, before entering the half-mile (2,400 foot) straight.

I have to admit, the GC SRT8 got a little silly on that last turn, even scaring me a bit as I nudged the edge of the pavement on exit. Later that day, after running the course with the Charger SRT8, 300C SRT8 and Viper SRT-10 Coupe, all of which felt more balanced and allowed for greater speed through all, especially that last corner, I managed to maintain better composure with the Grand Cherokee going around both turns two and nine, achieving higher speeds from finding the right line, so that the SUV didnt feel as if it was being pulled off balance. I have to say though, that this sport utility vehicle, normally set up to climb rocks and ford streams, could almost keep up to the amazingly agile Charger and 300 SRT8 sedans, both much lower to the ground and therefore less inclined to lateral gravitational forces. Consider that I was entering turn eight at about 130 mph and exiting at about 110 to 115, and feeling almost comfortable doing it, and youll get some idea of how good this SUV is at managing corners. This is why, on the road up from L.A., it hardly felt less capable than the aforementioned sedans.

Really, the only disappointment with the vehicle wasnt its performance, braking being equally as phenomenal as acceleration and handling, thanks to massive Brembos at all four corners. No, it comes down to interior quality, not fit and finish per se, which is quite good, but the ever-present cheap pickup truck grade plastics. Dash plastics have gone way down since the previous generation GC, and pretty well everywhere else, except for the window sills where bare arms often rest, less than premium surfaces abound. Why Jeep didnt step up to the plate and deliver a higher level of perceived quality probably comes down to the financial situation Chrysler Group was in when the SUV was under development four or five years ago, at which time such decisions would have been made, and therefore it is likely (and it comes from a good internal source that Im right on this guess) the brand is in the process of upgrading the plastics for the GCs mid-cycle upgrade, expected in a year. So, if cheap plastics dont bother you, this is probably the ultimate drivers SUV, price not even being an object. But if interior quality matters, youd be better off spending twice the price for the much slower Ranger Rover Sport Supercharged, or three times the price for that Porsche Cayenne Turbo S that matches the Jeeps acceleration - or better yet, giving $10 or 20K to a California chop-shop to install a customized full leather package to cover all the shiny vinyl and while their at it, replace the “environmentally friendly” faux woodgrain with some birds eye maple. Oh well, a guy can dream, cant he?

Still, the SRT8 cabin is much-improved over the stock Grand Cherokee, especially in the seating department. The Medium Slate leather buckets are incredibly supportive, with suede inserts to grip the hind section and massive lateral protrusions to keep the torso from sliding around, designed to hold occupants tightly in place even during hard cornering. Theyre heated too, of course.

Other niceties include faux carbon fiber on the instrument panel, shift knob and on the spokes of the leather-wrapped steering wheel, while the center console shifter-surround and door accents are finished in satin aluminum. So, understandably its easier to overlook the less than ideal plastics in the SRT8 than with other Grand Cherokee models, being that the upgrades improve the look, and in some cases feel of the interior dramatically.

Plastics aside, an even more persuasive argument that its easier to overlook small indiscretions in the GC SRT8 is that Jeep has made an SUV that beats the European premium brands at their own game, and is only charging half to one third the price. If it can get interior quality up, there wont be many reasons, other than prestige and the ability to go off-road, to opt for one of its pricier rivals. After all, other than trick hydraulic suspension systems, which make it so the Cayenne Turbo S and Ranger Rover Sport Supercharged SUVs can go off-road with the best of them, provided you swap wheels and tires so that you dont mess up the stock rims, while the Grand Cherokee SRT8 features all-wheel drive but is not Trail Rated, most of the standard and available goodies are the same or at least similar.

The top-tier Jeep features a voice-activated DVD navigation system, satellite radio connectivity, and U-Connect Bluetooth interactivity for ultimate wireless operation, plus of course, a superb Infinity audio system featuring a multi-disc stacker in the console. Of course theres a great deal more offered as standard, and yet other options, but why go on about such rudimentary elements when theres yet more performance details to discuss.

Throughout the review Ive made mention of a few items that probably deserve greater attention, the first of which are those giant Brembo brakes. They look gorgeous, poking through an elegant set of 20-inch five-spoke alloy rims, but the four-piston calipers arent painted red as on other SRT cars, but rather, black with Brembo etched in metal, to give a more upscale appearance. The rotors measure 360 mm (14.2 inches) in front and 350 mm (13.8 inches) in the rear, making it possible to pull the hefty SUV from 96 km/h (60 mph) to nil in about 125 feet.

Another specialized bit of Grand Cherokee SRT8 engineering is its new hybrid transfer case (and in this case hybrid doesnt refer to hybrid electric), derived by combining the front half of the lightweight stock unit and the rear half of a heavy-duty transfer case, the latter which contains the electronic components for the full-time four-wheel drive system. The change was necessary to compensate for the SRT8 6.1-liter engines 420 lb-ft of torque, and considering its beefier capabilities, which include a heavy-duty output shaft, its amazing that it came in 60 pounds lighter than the stock heavy-duty transfer case. Also, the stock rear differential has been exchanged for a Dana 44 from the Euro-only Grand Cherokee turbo diesel, plus a larger ring gear was added.

So how does it all work together? As Ive gone on and on about, taking you on a ride up the Angeles Crest and Angeles Forest highways to and then around Willow Springs earlier in this review, it works very well. I think what I like best is how its rear-wheel bias of about 90 to 95 percent, helps it to feel like a rear-drive vehicle. While I never encountered any slippery conditions, Im told that power can be apportioned to any wheel that finds grip making the vehicle an all-weather super-SUV.

That 6.1-liter engine isnt merely a bored and stroked 5.7-liter HEMI, although the SRT team did bore out the regular engines cylinder diameters by 3.5 millimeters (0.137 inches) apiece, modified the block with reinforcements and increased coolant flow. A forged steel crankshaft was added to minimize vibration, while stronger powder-metal connecting rods, capped off by oil squirter-cooled floating-pin pistons were incorporated. Also, a modified oil pan was put in place to reduce oil foaming.

Additionally, the cams were modified to increase engine speed and effectively produce greater horsepower, increasing the engines revs by 15 percent to almost 6,200 rpm - the 5.7-liter HEMI pegs the limiter at 5,400 rpm. Valve stems have been hollowed-out to reduce drag, due to their lighter weight, and then the empty cavities get filled with sodium for dissipating heat more effectively - who wouldve thought?

New high-flow cylinder heads were integrated for improved airflow, while larger diameter valves combined with reshaped cylinder ports and a redesigned intake manifold featuring larger diameter runners, for higher-speed tuning. The result of the SRT divisions work is a higher revving, quicker turning engine that resultantly produces much greater power than the stock 5.7, thanks also to a revised 9.6:1 to 10.3:1 compression ratio. Yes, while a lot of technical details they just go to show how much effort has gone in to create an engine capable of competing with the best premium SUVs in the business.

Lastly, I want to say a few words regarding how sensational the new Grand Cherokee SRT8 looks in all of its three exterior colors, Bright Silver, Brilliant Black and Inferno Red, and how all of its body-color bits and pieces, especially the grille, help give it a racy appearance. Slicing off the roof rack was a great way to improve aerodynamics and reduce wind howl, while making the SUV appear longer and even lower to the road than it already is. A deep front valance (actually an entirely new front clip) adds to the look while peeling air away from the front of the SUV and filtering it around its sides, where it helps, not hinders forward momentum, aided in the tail by a new, extremely sporty looking diffuser. Finishing off the rear end is a rather unique and utterly sporty combination of exhaust pipes comprised of two four-inch diameter chrome tips.

From every angle, the Grand Cherokee SRT8 is simultaneously one of the best and meanest looking SUVs on the planet, and the fact that it can be purchased for one third the price of the only competitor that can match its performance is simply astounding.