The Jeep Grand Cherokee SRT8 6.1i, produced between 2006 and 2010, represented the high-performance variant of the third-generation Grand Cherokee (WK). Positioned as the flagship model, the SRT8 aimed to blend the Grand Cherokee’s off-road capability and luxury with serious performance credentials. It was a direct response to growing demand for performance SUVs, competing with vehicles like the Porsche Cayenne and BMW X5 M. The SRT8 utilized a naturally aspirated 6.1-liter HEMI V8 engine, a significant upgrade over the base and mid-range engine options available in the WK series.
Technical Specifications
| Brand | Jeep |
| Model | Grand Cherokee |
| Generation | Grand Cherokee III (WK) |
| Type | SRT8 6.1i V8 (426 Hp) 4×4 Automatic |
| Start of production | 2006 |
| End of production | 2010 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | SUV |
| Seats | 5 |
| Doors | 5 |
| Fuel consumption (urban) | 21.8 l/100 km (10.8 US mpg, 13 UK mpg, 4.6 km/l) |
| Fuel consumption (extra urban) | 12.7 l/100 km (18.5 US mpg, 22.2 UK mpg, 7.9 km/l) |
| Fuel consumption (combined) | 16 l/100 km (14.7 US mpg, 17.7 UK mpg, 6.3 km/l) |
| Fuel Type | Petrol (Gasoline) |
| Acceleration 0 – 100 km/h | 5 sec |
| Acceleration 0 – 62 mph | 5 sec |
| Acceleration 0 – 60 mph | 4.8 sec |
| Maximum speed | 245 km/h (152.24 mph) |
| Emission standard | Euro 4 |
| Weight-to-power ratio | 5 kg/Hp, 198.6 Hp/tonne |
| Weight-to-torque ratio | 3.8 kg/Nm, 265.3 Nm/tonne |
| Power | 426 Hp @ 6000 rpm |
| Power per litre | 70.3 Hp/l |
| Torque | 569 Nm @ 4600 rpm (419.67 lb.-ft. @ 4600 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | ESF |
| Engine displacement | 6059 cm3 (369.74 cu. in.) |
| Number of cylinders | 8 |
| Engine configuration | V-engine |
| Cylinder Bore | 103 mm (4.06 in.) |
| Piston Stroke | 90.9 mm (3.58 in.) |
| Compression ratio | 10.3:1 |
| Number of valves per cylinder | 2 |
| Fuel injection system | Multi-port manifold injection |
| Engine aspiration | Naturally aspirated engine |
| Valvetrain | OHV |
| Engine oil capacity | 6.6 l (6.97 US qt | 5.81 UK qt) |
| Coolant | 14 l (14.79 US qt | 12.32 UK qt) |
| Kerb Weight | 2145 kg (4728.92 lbs.) |
| Max. weight | 2750 kg (6062.71 lbs.) |
| Max load | 605 kg (1333.8 lbs.) |
| Trunk (boot) space – minimum | 978 l (34.54 cu. ft.) |
| Trunk (boot) space – maximum | 1909 l (67.42 cu. ft.) |
| Fuel tank capacity | 80 l (21.13 US gal | 17.6 UK gal) |
| Length | 4785 mm (188.39 in.) |
| Width | 1870 mm (73.62 in.) |
| Height | 1710 mm (67.32 in.) |
| Wheelbase | 2781 mm (109.49 in.) |
| Front track | 1608 mm (63.31 in.) |
| Rear (Back) track | 1575 mm (62.01 in.) |
| Ride height (ground clearance) | 178 mm (7.01 in.) |
| Drag coefficient (Cd) | 0.39 |
| Minimum turning circle | 11.3 m (37.07 ft.) |
| Drive wheel | All wheel drive (4×4) |
| Number of gears | 5 |
| Gearbox type | automatic transmission |
| Front brakes | Ventilated discs |
| Rear brakes | Ventilated discs |
| Assisting systems | ABS (Anti-lock braking system) |
| Steering type | Steering rack and pinion |
| Tires size | 255/45 R20; 285/40 R20 |
| Wheel rims size | 20 |
Powertrain & Engine Architecture
The heart of the SRT8 was the 6.1-liter (370 cubic inch) HEMI V8 engine, internally designated as the ESF. This engine was a significant upgrade from the 4.7-liter and 5.7-liter HEMI engines offered in other Grand Cherokee trims. It featured a cast iron block, aluminum cylinder heads, and a hydraulic roller camshaft. The engine utilized a multi-port fuel injection system, delivering fuel directly into each intake port. The valvetrain employed an overhead valve (OHV) configuration with two valves per cylinder. The 6.1L HEMI produced 426 horsepower at 6,000 rpm and 420 lb-ft of torque at 4,600 rpm, providing substantial power for its class. The engine was mated to a five-speed automatic transmission (545RFE) specifically tuned for performance. This transmission featured a more aggressive shift schedule compared to the transmissions found in other Grand Cherokee models.
Driving Characteristics
The SRT8’s 6.1-liter HEMI and five-speed automatic delivered a markedly different driving experience than other Grand Cherokee variants. Acceleration was brisk, with 0-60 mph times consistently in the 4.8-5 second range. The automatic transmission, while smooth, prioritized performance over fuel economy, holding gears longer and downshifting quickly under throttle. Compared to the 5.7L HEMI, the SRT8 offered a noticeable increase in power and responsiveness. While the 5.7L provided adequate performance for everyday driving, the 6.1L transformed the Grand Cherokee into a genuinely quick SUV. The SRT8’s suspension was also tuned for performance, resulting in a firmer ride and reduced body roll compared to other trims. However, this came at the expense of some ride comfort.
Equipment & Trim Levels
The SRT8 came standard with a comprehensive list of features. Interior appointments included premium leather upholstery, heated and ventilated front seats, and unique SRT-specific badging. Standard exterior features included 20-inch alloy wheels, a distinctive SRT body kit (including a unique front fascia, side skirts, and rear spoiler), and quad exhaust outlets. Optional extras included a premium sound system, a navigation system, and rear-seat entertainment. The SRT8’s interior was designed to convey a sporty and luxurious feel, differentiating it from the more utilitarian trims.
Chassis & Braking
The SRT8 featured a modified chassis and braking system to handle the increased power. The suspension was lowered and stiffened, with firmer springs and dampers. Larger ventilated disc brakes were fitted at all four corners, providing improved stopping power. The SRT8 also benefited from a reinforced chassis structure to enhance rigidity and handling. The braking system included ABS (Anti-lock Braking System) as standard. The rear suspension utilized a multi-link design, contributing to improved handling and ride quality.
Market Reception & Comparison
The Jeep Grand Cherokee SRT8 was generally well-received by automotive critics. It was praised for its powerful engine, sporty handling, and luxurious interior. However, its fuel economy was a common criticism, as expected for a vehicle of its size and performance. Compared to the 5.7L HEMI Grand Cherokee, the SRT8 offered significantly more performance but at a higher price point and with reduced fuel efficiency. Against competitors like the Porsche Cayenne and BMW X5 M, the SRT8 offered a compelling combination of performance, luxury, and off-road capability at a more accessible price.
Legacy
The 6.1-liter HEMI engine in the SRT8 proved to be relatively reliable, although regular maintenance is crucial. The five-speed automatic transmission is also generally durable. Today, the SRT8 is gaining popularity among collectors and enthusiasts seeking a high-performance SUV with a unique character. Used examples are readily available, and prices vary depending on condition and mileage. The SRT8 represents a significant chapter in the Grand Cherokee’s history, demonstrating Jeep’s ability to create a genuinely capable and exciting performance SUV.
