The Isdera Imperator 108i, powered by a 5.6-liter V8 engine producing 365 horsepower, represents a unique chapter in German automotive history. Produced between 1984 and 1993, the Imperator was the flagship model of Isdera, a small, independent manufacturer founded by Eberhard Schultz. The 108i was not a mass-production vehicle; rather, it was a hand-built, low-volume grand tourer intended to evoke the spirit of the classic Mercedes-Benz 300SL Gullwing, and compete with established exotic car manufacturers. It was a statement of German engineering ambition, blending modern technology with a nostalgic design aesthetic.
Technical Specifications
| Brand | Isdera |
| Model | Imperator |
| Generation | Imperator |
| Type (Engine) | 108i 5.6 V8 (365 Hp) |
| Start of production | 1984 |
| End of production | 1993 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Coupe |
| Seats | 2 |
| Doors | 2 |
| Fuel Type | Petrol (Gasoline) |
| Acceleration 0 – 100 km/h | 4.8 sec |
| Acceleration 0 – 62 mph | 4.8 sec |
| Acceleration 0 – 60 mph | 4.6 sec |
| Maximum speed | 292 km/h (181.44 mph) |
| Weight-to-power ratio | 3.4 kg/Hp, 292 Hp/tonne |
| Power | 365 Hp |
| Power per litre | 65.2 Hp/l |
| Engine layout | Middle, Longitudinal |
| Engine Model/Code | M 117 |
| Engine displacement | 5600 cm3 (341.73 cu. in.) |
| Number of cylinders | 8 |
| Engine configuration | V-engine |
| Fuel injection system | Multi-port manifold injection |
| Engine oil capacity | 8 l (8.45 US qt | 7.04 UK qt) |
| Kerb Weight | 1250 kg (2755.78 lbs.) |
| Length | 4220 mm (166.14 in.) |
| Width | 1835 mm (72.24 in.) |
| Height | 1135 mm (44.69 in.) |
| Drivetrain Architecture | Rear wheel drive |
| Number of gears and type of gearbox | 5 gears, manual transmission |
| Front suspension | Coil spring |
| Rear suspension | Coil spring |
| Front brakes | Ventilated discs |
| Rear brakes | Ventilated discs |
| Assisting systems | ABS (Anti-lock braking system) |
Powertrain & Engine Architecture
The heart of the Isdera Imperator 108i is the Mercedes-Benz M117 5.6-liter V8 engine. This engine, originally designed for use in high-performance Mercedes-Benz models like the 560 SEC, was extensively modified by Isdera to increase its output to 365 horsepower. The M117 is a naturally aspirated, all-aluminum alloy engine featuring a single overhead camshaft per cylinder bank and Bosch K-Jetronic multi-port fuel injection. This mechanical fuel injection system, while sophisticated for its time, was known for its complexity and required precise maintenance. The engine’s longitudinal placement within the chassis, coupled with rear-wheel drive, contributed to the car’s balanced handling characteristics. The Imperator 108i exclusively utilized a 5-speed manual transmission, providing drivers with full control over the engine’s power delivery.
Driving Characteristics
The Isdera Imperator 108i offered a driving experience that blended grand touring comfort with genuine sports car performance. The 365 horsepower V8 provided strong acceleration, with a reported 0-60 mph time of around 4.6 seconds and a top speed of 181 mph. The manual transmission allowed for precise gear selection, maximizing the engine’s torque across a wide range of speeds. However, the car’s relatively heavy weight (approximately 2756 lbs) meant that it wasn’t as nimble as some contemporary sports cars. The suspension, utilizing coil springs all around, provided a comfortable ride, but wasn’t overly focused on track performance. The Imperator was designed for high-speed cruising on Autobahns and winding country roads, rather than aggressive cornering.
Equipment & Trim Levels
Given its limited production run and bespoke nature, the Isdera Imperator 108i wasn’t offered with traditional trim levels. Each car was largely customized to the buyer’s specifications. However, certain features were standard, including a luxurious leather interior, power windows, and air conditioning. The dashboard was designed with a functional, yet elegant aesthetic, featuring a comprehensive array of gauges. Optional extras included upgraded audio systems, custom paint colors, and unique interior trim materials. The overall ambiance was one of understated luxury, reflecting the car’s grand touring intentions.
Chassis & Braking
The Isdera Imperator 108i featured a steel space frame chassis, providing a rigid and lightweight foundation for the vehicle. The suspension utilized coil springs and shock absorbers at all four corners, offering a balance between comfort and handling. Braking duties were handled by ventilated disc brakes on all wheels, augmented by an ABS (Anti-lock Braking System) to enhance stopping power and stability. The car’s weight distribution was carefully optimized to improve handling balance, although the rear-biased weight distribution inherent in a front-engine, rear-wheel-drive layout was still noticeable.
Market Reception & Comparison
The Isdera Imperator 108i received a mixed reception from automotive critics. While praised for its striking design, powerful engine, and luxurious interior, it was also criticized for its high price tag and relatively unsophisticated technology compared to some of its Italian and British rivals. The car’s reliance on a modified Mercedes-Benz engine and chassis components was seen by some as a lack of originality. Compared to other grand tourers of the era, such as the Porsche 928 or the Ferrari 365 GTB/4 Daytona, the Imperator offered a unique blend of German engineering and classic styling, but lacked the established brand recognition and performance pedigree of its competitors.
Legacy
The Isdera Imperator 108i remains a rare and collectible automobile. Fewer than 30 examples were produced during its production run, making it a highly sought-after vehicle among enthusiasts of classic German sports cars. The car’s long-term reliability is generally considered to be good, thanks to the robust design of the Mercedes-Benz M117 engine and the high quality of the materials used in its construction. However, maintaining the K-Jetronic fuel injection system can be challenging, requiring specialized knowledge and expertise. Today, the Imperator 108i represents a unique and fascinating chapter in automotive history, a testament to the vision and ambition of Eberhard Schultz and the enduring appeal of the classic German grand tourer.
