Holding on to the wheel of Jeep's utterly mad HEMI V8-powered four-wheel drive brute
Zlatko Mulabegovic

Back in a not too distant 2006, Jeep seriously stunned the performance SUV market by introducing their Grand Cherokee SRT8. Powered by a high-output, 420 horsepower 6.1-liter HEMI engine, the new Cherokee was based on a rather simple concept and, without too much interference from the few electronic safety aids, it boasted both great performance and driving pleasure as a result. This is the most powerful Jeep vehicle to date and the ultimate performance sport utility vehicle, marrying the Cherokee’s proverbial versatility with high-power performance brought by the SRT8 powerplant.

On the outside
The exterior of the SRT8 has performance written all over it, with a much lower stance, a deeper front bumper, a more aggressive grille, twin center exhausts, and the SRT8 badges. Further contributing to its aggressive stance are the unique forged 20-inch five-spoke aluminum wheels shod with high-performance Goodyear W-rated four-season tires with run-flat capability. The SRT8 surely does not possess the refinement of its counterparts from Porsche or BMW, but it does surely convey the impression of the bad boy or even hooligan it happens to be. As in the rest of the package, a sporty simplicity prevails, but there are enough visual clues as to the nature of the beast.

The cabin
Nothing much to report from here, as the cabin of the SRT8 is the least exciting bit of the whole car. No flashy stuff here, just pure simplicity and function, as if most of the development time were used to make the car go faster. To complement that philosophy, you get a 300 km/h speedometer, power adjustable, deeply sculpted performance front seats, as well as “carbon fiber” finish on the steering wheel and gear knob.

Under the hood
The engine is the centerpiece of this car and what makes it so desirable. The specially tuned version of the new 6.1-liter SRT HEMI engine provides plenty of horsepower and torque to the unique SRT four-wheel drive system. The new motor employs hemispherical combustion chambers that provide power and efficiency, while retaining classic HEMI looks, including the orange-painted cylinder block and black valve covers. SRT engineers extracted 85 more horsepower over the Jeep Grand Cherokee's 5.7-liter HEMI by adding more cubic inches, increasing the compression ratio, redesigning the cylinder head, intake and exhaust systems for increased flow, and increasing engine speed. The bore was increased by 3.5 millimeters in order to increase the total displacement to 6.1 liters from the original 5.7 liters; compression ratio was also increased to 10.3:1 from 9.6:1, increasing engine efficiency, power and responsiveness.

The list of factory-performed performance modifications include higher flow cylinder heads, a cold air induction system, specially designed intake manifold, high flow headers, catalyst and exhaust system. New profile and more aggressive camshafts were fitted, allowing the engine to rev higher and longer; the rpm limiter is set at 6,000 rpm as opposed to the original 5,000 rpm redline. All components were strengthened, and forged internals were used in search of more power and less weight, especially on the rotating components.

Power from the SRT 6.1-liter HEMI is sent through a special torque converter to an SRT-upgraded A580 five-speed automatic transmission and over to front and rear differentials through a specially designed transfer case. Traction is excellent and slip free, giving the Jeep a mad launch off the line and enabling it to hit the 100 km/h mark in only 4.6 seconds; top speed is at 265 km/h, as tested on U.A.E. roads.

The stiff stuff
Chassis and suspension were also tuned taking into consideration the increased performance, with SRT-tuned dampers, unique sway bars and specially tailored spring rates and suspension bushings. New front suspension knuckles feature a camber angle calibrated for optimum suspension performance. The ride height of the SRT8 is one inch lower than the standard issue Jeep Grand Cherokee, which lowers aerodynamic drag, centre of gravity and contributes to the vehicle's aggressive stance. Same goes for the Electronic Stability Program that was specially calibrated for the performance SUV, keeping both its dynamic requirements and the fun factor in mind.

The braking system is another highlight of this SUV, designed to provide outstanding capability as a counterpoint to the vehicle's awesome launch and acceleration. All four wheels feature four-piston performance brake calipers developed by Brembo, finished in gloss red. Under braking, these calipers clamp down on 360 x 32mm vented rotors up front, with 350 x 28mm vented rotors in the rear.

At the wheel
To say that the Grand Cherokee SRT8 is fun to drive would be an understatement; this is a mad car and rates very high on the fun factor. First of all, having all of that power on tap is enough to maintain a stupid grin on your face, while the massive grip and well tuned suspension provide even more entertainment while cornering hard. Finally, the highly efficient Brembo brakes are capable of stopping this heavy bullet safely and take any unwanted drama out of the equation. The overall experience is nothing short of exhilarating, further boosted by a throaty engine note and the sporty exhaust system.

Our verdict
This is the best performance SUV for the money and, if you’re not too stuck on fancy leather interiors and technologically advanced solutions, the SRT8 will delight you with its explosive nature, plenty of power on tap, great handling and more driver delights. This car is as pure as it gets, free of inhibitions and restrictions, and built with only one purpose in mind – to go damn fast!