UNUSUAL CARS MODEL GUIDE
The Mercedes-Benz SLK 55 AMG R171 placed a naturally aspirated 5.4-litre V8 in a compact two-seat roadster. Launched in 2004 with 265 kW (360 PS), 510 Nm and a seven-speed automatic, it offered a combination no direct rival matched: folding-metal-roof practicality, a large-capacity AMG engine and a short wheelbase.
Quick answer: The standard SLK 55 is the usable road car, while the rare Black Series is lighter, more powerful and has a fixed carbon roof. Buyers should examine body condition, roof operation, engine leaks and cooling, transmission servicing, suspension, brakes, tyres and the originality of AMG-specific parts.
Featured photograph by Calreyn88, CC BY-SA 4.0, via Wikimedia Commons; locally hosted and cropped to 1200 × 675 pixels.
The V8 SLK idea
The second-generation R171 SLK arrived with more angular styling and an improved folding Vario-roof. AMG then installed the M113 5.4-litre V8 without a supercharger. The engine’s 360 PS output was less dramatic than contemporary supercharged AMG saloons, but the SLK’s compact dimensions and 510 Nm torque made it exceptionally quick and characterful.
Specifications and versions
| Version | Engine and output | Main distinction |
|---|---|---|
| SLK 55 AMG | 5.4-litre M113 V8; 265 kW / 360 PS; 510 Nm | Retractable metal roof and seven-speed automatic |
| SLK 55 AMG Black Series | 5.4-litre V8; 294 kW / 400 PS; 520 Nm | Fixed carbon roof, reduced weight and sharper chassis |
| 2008 facelift | Standard V8 drivetrain retained | Revised styling, steering and detail updates |
How the SLK 55 drives
The SLK 55 is more muscle car than delicate roadster. Its naturally aspirated V8 responds instantly, the short wheelbase makes direction changes eager and the seven-speed gearbox keeps the engine in its broad torque band. The ride is firm and the steering less communicative than the best pure sports cars, but the engine, size and all-weather roof give it a distinctive appeal.
Love cars you don’t see every day?
Get forgotten cars, surprising motoring stories and the most interesting finds from Unusual Cars by email.
Free to join. No spam. Unsubscribe whenever you like. See our privacy policy.
The SLK 55 AMG Black Series
Mercedes-AMG identifies the 2006 SLK 55 Black Series as the first model to carry the Black Series name. It replaced the retractable roof with a fixed carbon-fibre hardtop, added carbon front wings and side vents, removed the fog lights for cooling and fitted 19-inch forged wheels. Output rose to 294 kW (400 PS) and torque to 520 Nm. It is a specialised collector car rather than a simple trim level.
Mercedes SLK 55 AMG R171 buying guide
Inspect front wings, arches, sills, boot edges, floor seams and suspension mounting points for corrosion or previous repair. Operate the Vario-roof repeatedly, checking seals, hydraulic movement, boot dividers and drain paths. Water in the boot can damage electronics, so lift trim where practical and look for staining.
The M113 V8 is generally robust when maintained, but check for oil leaks, coolant loss, tired engine mounts, noisy auxiliary components and evidence of overheating. The seven-speed automatic needs clean, consistent shifts when cold and hot. Confirm that servicing has not been treated as “sealed for life”.
Listen for suspension knocks, inspect tyres for inner-edge wear and check discs, pads and brake lines. Test air conditioning, heated seats, windows, instruments and every roof-related switch. Original wheels, exhaust, bumpers, brakes and interior trim add value, particularly because many cars have been modified.
Standard car or Black Series?
For regular road use, the standard SLK 55 offers the complete idea: compact dimensions, open-air driving and a large naturally aspirated V8. The Black Series is rarer and historically important, but its fixed roof removes the feature that defines an SLK. A standard, unmodified car with excellent history is the realistic target for most buyers.
Research sources
Continue the Mercedes-Benz story
Explore the Rare & Performance Mercedes-Benz hub, then compare the SLK 32 AMG R170 and CLK DTM AMG.
Frequently asked questions
What engine is in the R171 SLK 55 AMG?
It uses a naturally aspirated 5.4-litre M113 V8.
How much power does the SLK 55 AMG have?
The standard R171 produces 265 kW, or 360 PS, with 510 Nm of torque.
Does the SLK 55 have a folding metal roof?
Yes. The standard car has a retractable Vario-roof; the Black Series uses a fixed carbon roof.
Why is the Black Series important?
Mercedes-AMG identifies it as the first model to use the Black Series name.
What should buyers inspect first?
Check corrosion, roof operation and water leaks, engine and transmission condition, suspension, brakes, tyres and genuine AMG parts.
