Carlsson Mercedes-Benz CLS (2005) Review & Specs

Introduction

The Carlsson Mercedes-Benz CLS (2005) represents a distinctive interpretation of the W219-generation CLS four-door coupé, modified by the German tuning specialist Carlsson Autotechnik. Carlsson, founded in 1989 by brothers Rolf and Andreas Hartge in Merzig on the German-French-Luxembourg border, specialises exclusively in Mercedes-Benz vehicles. For the newly launched CLS, Carlsson introduced its tuning programme in April 2005, with the CK55 package based on the CLS 55 AMG serving as the flagship offering.

What distinguishes the Carlsson CLS from a standard W219 is the combination of verified performance upgrades, aerodynamic enhancements, and interior refinements. The CK55 package raises the CLS 55 AMG's supercharged V8 output from 476 PS to 560 PS, while the CM50 K package based on the CLS 500 adds a supercharger system to produce 430 PS. Buyers considering this vehicle should understand that Carlsson offered its components both as complete packages and as individual items, meaning individual examples may differ significantly in specification. Verifying the authenticity and completeness of the Carlsson conversion is therefore essential before purchase.

Exterior Design and Dimensions

The Carlsson CLS is built on the W219 platform, which Mercedes-Benz introduced in 2004 as a completely new four-door coupé concept combining the elegance of a coupé with the practicality of a saloon. The W219 featured a distinctive profile with a low roofline, frameless side windows, and a long bonnet. The standard CLS measures approximately 4,913 mm in length, 1,873 mm in width, and 1,403 mm in height, with a wheelbase of 2,854 mm. These dimensions were shared with the E-Class upon which it was based, though the CLS was both lower and wider to achieve its distinctive proportions.

Carlsson's exterior modifications for the CLS include an RS front-spoiler lip that continues the lines of the CLS harmoniously while reducing lift for improved handling. A sports rear silencer with four tailpipes dominates the rear view. These exhaust components are made entirely of stainless steel, with double-walled tailpipes that are thermally insulated and more aerodynamic, resulting in less dirt accumulation from turbulence. The vehicle rides on forged wheels from the Carlsson 'Ultra Light' series, available in 8.5 x 20-inch dimensions at the front and 11 x 20-inch at the rear, fitted with Dunlop SP Sport Maxx tyres in 255/30 ZR20 and 305/25 ZR20 sizes respectively. The C-Tronic SUSPENSION supplementary control unit lowers the CK55 by approximately 30 mm, with an intelligent electronic system that automatically adjusts suspension travel on poor road surfaces.

Interior, Comfort, and Practicality

The interior of the Carlsson CLS starts with the already well-appointed W219 cabin and is enhanced by Carlsson with high-quality materials. An exclusive range of interior appointments is available, with a characteristic combination of high-quality Carlsson leather and Alcantara in anthracite with rhombus quilting. To match the upholstery, the standard trim parts are finished in black piano varnish, and an ergonomically designed Carlsson sports steering wheel with Alcantara covering provides a secure grip.

The W219 CLS is a four-seat four-door coupé, with the rear bench designed to accommodate two passengers in comfort rather than three. The cabin offers a driver-oriented dashboard with COMAND infotainment, electrically adjustable seats, and a range of luxury appointments typical of Mercedes-Benz vehicles of this era. Practical limitations are inherent in the four-door coupé concept: the sloping roofline reduces rear headroom compared with a conventional saloon, and the boot, while reasonably sized, has a relatively high load lip. Carlsson's interior modifications do not significantly alter the vehicle's practicality, though the leather and Alcantara appointments and black piano varnish trim add a more luxurious and sporting character.

Technology, Ownership, and Maintenance

Ownership of a Carlsson-modified CLS requires attention to both the standard W219 maintenance schedule and the specific requirements of the Carlsson components. Routine servicing for the CLS 500 and CLS 55 AMG includes oil and filter changes at recommended intervals, with spark plugs and air filters replaced at longer intervals. The CLS 500 is powered by the M 113 5.0-litre V8 producing 306 PS, while the CLS 55 AMG uses a supercharged 5.4-litre V8 producing 476 PS. Both models were equipped with the 7G-Tronic seven-speed automatic transmission, with the AMG variant using a five-speed Speedshift automatic.

Carlsson-specific components demand particular attention. The C-Tronic SUSPENSION module interacts with the factory AIRMATIC system and should be checked for correct operation and fault codes. The sport exhaust system, with its four tailpipes, should be inspected for corrosion and secure mounting. Carlsson forged alloy wheels in 20-inch dimensions are susceptible to kerb damage and require careful inspection for cracks or deformation. On supercharged CM50 K models, the supercharger system and intercooler should be checked for correct operation and oil leaks.

Parts availability for the base W219 CLS is generally good through Mercedes-Benz dealerships and independent specialists. Carlsson-specific parts, however, may be more difficult to source, particularly the aerodynamic components, forged wheels, and exhaust systems. Prospective buyers should confirm that any required Carlsson parts are available or that suitable alternatives exist. Documented mechanical concerns for the W219 CLS include AIRMATIC suspension faults and the complexity of the electronic systems, which can lead to costly repairs if neglected. These are general W219 considerations and not specific to the Carlsson conversion.

Carlsson Mercedes-Benz CLS (2005) Specifications and Performance

Carlsson offered several performance packages for the W219 CLS. The flagship CK55 is based on the CLS 55 AMG, which in 2005 was powered by a supercharged 5.4-litre V8 engine producing 476 PS (350 kW) and 700 Nm of torque in standard form. Carlsson's CK55 engine kit increases output to 560 PS (412 kW) at 6,000 rpm, with torque rising to 810 Nm at 2,600 rpm. Carlsson quotes a 0–100 km/h acceleration time of 4.5 seconds and a top speed of 320 km/h (electronically limited) for the CK55.

The CM50 K package is based on the CLS 500 and its 5.0-litre V8. Carlsson adds a supercharger system developed in close cooperation with Ogura Clutch, raising output from 306 PS to 430 PS (316 kW), with torque increasing from 460 Nm to 650 Nm at 2,800 rpm. Carlsson quotes a 0–100 km/h acceleration time of 5.2 seconds for the CM50 K. These are Carlsson's verified figures for each conversion and should not be confused with the factory specifications of the base models.

Carlsson also offered the C-Tronic Diesel Power module for the CLS 320 CDI, increasing the 3.0-litre V6 diesel's output from 224 PS to approximately 280–290 PS based on owner reports, with torque rising significantly from the standard 540 Nm. This module is a plug-and-play auxiliary control unit that can be installed without mechanical changes to the engine.

Specifications Table

Specification	Carlsson CK55 (2005)
Make and model	Carlsson Mercedes-Benz CLS (CK55, based on CLS 55 AMG W219)
Model year	2005
Generation	W219 (first-generation CLS)
Body style	Four-door coupé
Engine	5.4-litre V8, supercharged, petrol
Engine displacement	5,439 cc
Maximum power (Carlsson CK55)	560 PS (412 kW) at 6,000 rpm
Maximum torque (Carlsson CK55)	810 Nm at 2,600 rpm
Standard CLS 55 AMG power (for reference)	476 PS (350 kW)
Transmission	AMG five-speed Speedshift automatic
Drivetrain	Rear-wheel drive
Acceleration 0–100 km/h	4.5 seconds (Carlsson figure)
Maximum speed	320 km/h (electronically limited)
Length	4,913 mm
Width	1,851 mm (CK55 specification)
Height	1,373 mm (CK55 specification)
Wheelbase	2,854 mm
Kerb weight (CLS 55 AMG reference)	1,730 kg

City Driving and Highway Use

The Carlsson CLS is a large four-door coupé with dimensions that reflect its positioning as a luxury grand tourer. At approximately 4.9 metres in length and 1.85 metres in width, it requires care in tight urban environments. The low roofline and thick A-pillars can restrict visibility at junctions and in multi-storey car parks, and the 30 mm suspension lowering reduces ground clearance, making speed humps and steep driveways potential concerns.

In city traffic, the automatic transmission provides smooth, unobtrusive shifts, and the torque-rich V8 allows the car to move easily at low speeds. Fuel consumption in urban conditions will be high, as expected from a large V8-engined luxury coupé. Official figures for the standard CLS 500 quote approximately 16.8 l/100 km in city driving and 11.3 l/100 km combined, and the Carlsson conversions are unlikely to improve these figures.

On the highway, the Carlsson CLS comes into its own. The combination of high torque, a long-legged automatic transmission, and aerodynamic enhancements makes it an accomplished long-distance tourer. The lowered suspension and Carlsson chassis components are intended to reduce body roll and improve high-speed stability, while the supercharged V8 provides effortless overtaking ability. The low-profile 20-inch tyres may transmit more road noise and impact harshness than standard fitments, particularly on coarse surfaces.

Safety Equipment and Pre-Purchase Inspection

The W219 CLS was equipped with a comprehensive suite of safety features for the 2005 model year. Standard safety equipment includes ESP electronic stability control, ABS with brake assist, dual-stage front airbags, side airbags, window airbags, and seat belt pretensioners with force limiters. The CLS also featured PRE-SAFE anticipatory occupant protection, which can detect an impending collision and prepare the vehicle's safety systems accordingly. Adaptive brake lights and bi-xenon headlamps with Active Light System were available as optional equipment. Carlsson modifications do not typically alter the factory safety systems, but any changes to suspension, wheels, or tyres should be assessed for their effect on vehicle dynamics and safety system calibration.

When inspecting a Carlsson CLS, the following checks are recommended:

• Service history: Confirm regular maintenance at correct intervals, with invoices from Mercedes-Benz specialists or Carlsson-approved workshops.
• Supercharger system: On CK55 and CM50 K models, inspect the supercharger for correct operation, unusual noises, and oil leaks. Verify that the intercooler and associated pipework are intact and correctly installed.
• Engine condition: Check for oil leaks, coolant leaks, and signs of overheating. Listen for unusual noises from the timing chain and valvetrain.
• Transmission: Test the automatic transmission for smooth shifting in all modes, checking for hesitation or harsh engagement.
• Suspension: Verify correct operation of the AIRMATIC system and the Carlsson C-Tronic module. Check for fault messages and uneven ride height.
• Exhaust system: Inspect the Carlsson sport exhaust for corrosion, cracks, and secure mounting of the four tailpipes.
• Wheels and tyres: Examine Carlsson forged alloy wheels for cracks, kerb damage, and correct tyre sizes. Confirm the tyres are matched and within legal tread depth.
• Body and paint: Check for accident damage and verify the authenticity of Carlsson body components. Look for uneven panel gaps or evidence of poor repair.
• Interior: Verify the condition of Carlsson-specific leather and Alcantara trim, steering wheel, and piano varnish trim. Check all electronic functions, including COMAND, climate control, and seat adjustment.
• Documentation: Confirm that the Carlsson conversion is documented and that any applicable Mercedes-Benz recalls have been completed.

Trims, Versions, and Tuning Packages

Carlsson offered several tuning packages for the W219 CLS, and it is important to distinguish between them. The CK55, based on the CLS 55 AMG, is the flagship performance package, with 560 PS and 810 Nm achieved through a revised supercharger system and engine management recalibration. The CM50 K, based on the CLS 500, adds a supercharger system developed with Ogura Clutch to produce 430 PS and 650 Nm. The C-Tronic Diesel Power module for the CLS 320 CDI is a plug-and-play electronic upgrade that increases the diesel V6's output without mechanical changes.

It is important to note that individual cars may have been modified with a selection of Carlsson components rather than a complete package, and some may have had modifications applied after initial delivery. The C-Tronic suspension, for example, can be fitted independently of the engine tuning. The aerodynamic package and alloy wheels are also available separately. Prospective buyers should request documentation of the specific Carlsson work performed and verify that the components fitted match the claimed package.

Advantages and Disadvantages

Advantages

• Substantial performance increase over the standard CLS 55 AMG, with 560 PS and 810 Nm from the CK55 package, delivering supercar-rivalling acceleration and a 320 km/h top speed.
• Distinctive and exclusive appearance thanks to Carlsson aerodynamic components, 20-inch forged Ultra Light alloy wheels, and interior trim details including anthracite leather and Alcantara with rhombus quilting.
• Based on the W219 CLS, which offers a unique four-door coupé body style with a high level of luxury, technology, and standard safety equipment.

Disadvantages

• Carlsson-specific parts, particularly the supercharger system, forged wheels, and aerodynamic components, can be difficult to source and expensive to replace compared with standard Mercedes-Benz parts.
• The lowered suspension and 20-inch wheels with low-profile tyres reduce ride comfort and increase the risk of wheel damage on poor road surfaces.
• Fuel consumption is high, and the complexity of both the W219 platform and the Carlsson modifications can lead to significant maintenance and repair costs.

Final Verdict

The Carlsson Mercedes-Benz CLS (2005) is a compelling proposition for buyers seeking a luxury four-door coupé with exceptional performance and a high degree of exclusivity. The CK55 package transforms the already formidable CLS 55 AMG into a genuine supercar in a luxury saloon package, with verified performance figures that place it among the fastest four-door vehicles of its era. The combination of a supercharged 560 PS V8, Carlsson chassis enhancements, and a bespoke interior makes it a genuinely special vehicle, while the CM50 K offers a more accessible route to Carlsson ownership.

However, prospective buyers should approach any Carlsson-modified CLS with caution. The modifications add complexity and potential maintenance burden, and the condition of the specific example is more important than the badge. A well-documented car with a complete service history and evidence of proper care is essential. Buyers should budget for the possibility of expensive repairs to the supercharger, suspension, or engine management systems, and should verify that all Carlsson components are present, functional, and correctly installed. This is not a car for the faint-hearted, but for the right buyer, it offers a rare blend of luxury, performance, and individuality in a distinctive four-door coupé package.

Frequently Asked Questions

What engine does the Carlsson CK55 have?

The Carlsson CK55 is based on the Mercedes-Benz CLS 55 AMG and retains its supercharged 5.4-litre V8 engine with a displacement of 5,439 cc. Carlsson's CK55 engine kit increases output from 476 PS to 560 PS, with torque rising from 700 Nm to 810 Nm.

What should buyers inspect before purchasing a Carlsson CLS?

Buyers should verify the authenticity of the Carlsson conversion through documentation, check the condition of Carlsson-specific components such as the supercharger, forged wheels, exhaust, and suspension, and confirm that the base W219 CLS has a full service history. A thorough inspection of the AIRMATIC suspension and automatic transmission is also recommended.

What distinguishes the Carlsson CK55 from a standard CLS 55 AMG?

The CK55 features the performance kit producing 560 PS instead of 476 PS, Carlsson RS front-spoiler lip, a sports rear silencer with four tailpipes, C-Tronic suspension lowering by approximately 30 mm, 20-inch forged Ultra Light alloy wheels, and interior appointments including anthracite leather and Alcantara with rhombus quilting and black piano varnish trim.