Review: Mercedes C209 CLK 55 & CLK 63 AMG Coupe

Review: Mercedes C209.I CLK 55 AMG Coupe (2002-05)

Overview

Released in Australia in October 2002, the Mercedes-Benz C209 CLK 55 AMG was a four-seat, performance coupe. Manufactured in Germany, the rear-wheel drive C209 CLK 55 AMG Coupe was powered by a 5.4-litre V8 petrol engine that was mated to a five-speed automatic transmission.

M113.987 V8 engine

Assembled by hand, the 5439 cc M113.987 V8 engine had a die-cast alloy block with 97.0 mm bores and a 92.0 mm stroke, cast-in Silitec cylinder liners, fracture-split forged steel connecting rods, iron-coated aluminium pistons with oil spray cooling, an alloy cylinder head, a single overhead camshaft (SOHC) per cylinder bank driven by a double-roller chain, three valves per cylinder (two intake, one exhaust) actuated by roller rockers, two-spark plugs per cylinder, a dual-length intake manifold and a compression ratio of 11.0:1. Maximum engine speed was 6700 rpm.

The C209 CLK 55 AMG Coupe could accelerate from rest to 100 km/h in 5.2 seconds and had an electronically-limited top speed of 250 km/h. Over the combined NEDC test cycle, fuel consumption was 12.8 litres per 100 km.

Transmission

The five-speed automatic transmission had a single-plate dry clutch with the following gear ratios: 3.60 (1st), 2.19 (2nd), 1.41 (3rd), 1.00 (4th) and 0.83 (5th); the final drive ratio was 3.06. The transmission also featured a ‘Speedshift’ manual shift mode that could be activated by pressing the program select button on the automatic selector lever. Then, the right and left switches positioned behind the top two steering wheel spokes could be used for up- and down-shifts, respectively.

Dimensions and body

Compared to its C208 CLK 55 AMG predecessor, the Mercedes-Benz C209 CLK 55 AMG Coupe was 71 mm longer (at 4638 mm), 18 mm wider (1740 mm), 43 mm taller (1414 mm) and had a 25 mm longer wheelbase (2715 mm); kerb weight increased by 95 kg to 1715 kg. According to Mercedes-Benz, the body of the C209 CLK Coupe was 40 per cent torsionally stiffer than its C208 predecessor, in part due to:

• 40 per cent of the bodyshell consisting of high-strength steel alloys (compared to 22 per cent for the C208);
• single-piece sidewall paneling with individually welded inner shells;
• high-strength steel tubing for the A-pillars;
• a solid square section below the dashboard bolted to both A-pillars; and,
• welded high-strength tubing for the B-pillar stumps.

Relative to the C209 CLK Coupe , the CLK 55 AMG Coupe could be identified by its AMG body-styling for the front apron, rear apron and side skirts and its AMG exhaust system with twin tailpipes. Furthermore, the spoiler lip on the boot lid reduced the lift acting on the rear axle by over 50 per cent.

Suspension

The Mercedes-Benz C209 CLK 55 AMG Coupe had three-link front suspension with MacPherson struts, coil springs, twin-tube gas-pressure shock absorbers and an anti-roll bar. The multi-link rear suspension, however, had coil springs, single-tube gas-pressure shock absorbers and an anti-roll bar.

Steering

The Mercedes-Benz C209 CLK 55 AMG Coupe had rack-and-pinion steering with speed-sensitive power assistance.

Safety equipment

Standard safety equipment for the Mercedes-Benz CLK 55 AMG Coupe included dual front airbags (with two-stage deployment), front and rear side airbags, full-length curtain airbags (i.e. for front and rear occupants), ABS, brake assist, electronic stability control, traction control and seatbelts with pre-tensioners and load limiters for all seats.

Features: Mercedes-Benz CLK 55 AMG Coupe

Standard features for the Mercedes-Benz CLK 55 AMG Coupe included 18-inch AMG alloy wheels (7.5J x 18 front and 8.5J x 18 rear) with 225/40 R18 front and 255/35 R18 rear tyres, a seven speaker sound system with a ten-disc CD changer, Mercedes-Benz’s COMAND APS (Cockpit Management and Data System) with satellite navigation and TV receiver, dual-zone climate control air conditioning (‘Thermotronic’), two-tone nappa and nubuk leather upholstery, front AMG sports seats with power adjustment and heating, cruise control (‘Speedtronic’), bi-xenon headlights, front fog lights, automatic headlights, rain-sensing wipers, a leather-wrapped AMG steering wheel, split and folding rear seats, remote central locking, power adjustable and heated mirrors with automatic dipping on reverse, power windows, a power adjustable steering column (for height and reach), memory settings (for the front seats and steering wheel), a glass tilting/sliding sunroof, tinted windows, aluminium interior trim, a trip computer and immobiliser.

Inside, the CLK 55 AMG Coupe featured nubuk leather for the door panels and perforated seat cushions – available in anthracite, merlot red or dark blue shades – and nappa leather in anthracite for all other leather surfaces.

Updates

In July 2004, the seven speaker sound system with ten-disc CD changer (the latter in the glovebox) was replaced by a six speaker sound system with a six-disc in-dash CD player. From January 2005, the CLK 55 AMG Coupe was fitted with rear parking sensors.

Review: Mercedes C209.II CLK 55 and CLK 63 AMG Coupe (2005-09)

Overview

Released in August 2005, the Mercedes-Benz C209 Series II (C209.II) CLK 55 AMG introduced updated styling, upgraded electronics and additional features. Visually, the C209.II CLK Coupe could be identified by its redesigned ‘wedge shaped’ front bumpers and larger airdam.

Like the C209.II CLK Coupe, the C209.II CLK 55 AMG was fitted with a MOST (Media Oriented Serial Transport) media system which included an upgraded DVD-based navigation system; the CAN-bus (controller area network) was also upgraded for greater reliability.

In August 2006, the CLK 63 AMG Coupe – powered by the 6.2-litre M156 V8 petrol engine – replaced the CLK 55 AMG. Relative to the CLK 55 AMG, the CLK 63 AMG was 60 kg heavier, with a kerb weight of 1755 kg.

CLK 63 AMG Coupe: M156.982 V8 engine

Developed and hand-assembled by Mercedes-AMG in Affalterbach, Germany, the 6208 cc M156.982 V8 petrol engine had an aluminium-silicon alloy (AlSi7) block which had 102.2 mm bores and a 94.6 mm stroke, an aluminium-silicon alloy (AlSi17) cylinder head, a Cromax 42CrMo4V forged steel alloy crankshaft, fracture-split forged connecting rods, cylinder bores with twin-wire-arc-sprayed (TWAS) coating, Bosch 9.7 engine management system, double overhead camshafts per cylinder bank (intake cams driven by a double chain from the crankshaft and small gears on the intake cams drive the exhaust camshafts), continuously variable intake and exhaust camshafts (over a range of 40 degrees via electrohydraulic vane-type adjusters), four valves per cylinder (40 mm intake valves and 34 mm exhaust valves) with bucket tappets, a magnesium variable intake manifold (with two integral throttle flaps) and a compression ratio of 11.3:1. Maximum engine speed for the M156 V8 engine was 7200 rpm.

The CLK 63 AMG Coupe could accelerate from rest to 100 km/h in 4.6 seconds; its top speed was electronically limited to 250 km/h. Over the combined EUDC test cycle, fuel consumption was 14.2 litres per 100 km.

CLK 63 AMG Coupe: AMG Speedshift 7G-Tronic transmission

For the seven-speed ‘AMG Speedshift Plus 7G-Tronic’ automatic transmission, the gear ratios were 4.38 (1st), 2.86 (2nd), 1.92 (3rd), 1.35 (4th), 1.00 (5th), 0.87 (6th) and 0.73 (7th), while the final drive ratio was 2.65. Furthermore, the driver could perform gearshifts using the steering wheel paddles and select from three drive programs:

• Comfort, ‘C’, for softer throttle response, smooth gearshifts and early upshifts to minimise fuel consumption;
• Sport, ‘S’, for greater throttle response, higher engine speeds before upshifting and gearshifts that were around 30 per cent faster than in Comfort; and,
• Manual, ‘M’, for gearshifts via the paddles, maximum throttle response and gearshifts that were around 20 per cent faster than in Sport.

The transmission also featured an automatic throttle-blipping function during downshifts for almost jolt-free gearshifts and to reduce load-change responses.

Safety equipment

Compared to its C209.I predecessor, safety equipment for the C209.II CLK 55 AMG Coupe was improved with the introduction of active front seat head restraints (Mercedes-Benz’s ‘Neck-Pro’).

Brakes: CLK 55 AMG and CLK 63 AMG

For the C209.II CLK 55 AMG, the braking package was upgraded with six-piston front callipers and four-piston rear callipers; dimensions continued to be 345 mm by 30 mm for the front discs and 300 mm by 22 mm for the rear.

Upon its release in 2006, the CLK 63 AMG had the same braking package as the C209.II CLK 55 AMG.

Features: CLK 55 AMG and CLK 63 AMG Coupes

Compared to its C209.I predecessor, standard features for the CLK 55 AMG Coupe were extended to include a Harman Kardon Logic7 surround sound system, tyre pressure monitoring and anti-theft alarm system.

Upon its introduction, the CLK 63 AMG had similar features to the CLK 55 AMG. Changes, however, included new AMG sports seats, Nappa leather upholstery (in black, basalt grey or sand), new contoured steering wheel with perforated leather sections, aluminium gearshift paddles and polished stainless steel sports pedals.

Mercedes-Benz CLK 63 AMG Black Series

Released in Australia in early 2008, the CLK 63 AMG Black Series was based on the Formula One safety car. Compared to the standard CLK 63 AMG, the Black Series had a more powerful engine due to its:

• Redesigned air intake with larger ducts;
• AMG sports exhaust with full-length twin pipes; and,
• Recalibrated engine control unit.

For greater acceleration, the gear ratios were revised – 4.38 (1st), 2.86 (2nd), 1.92 (3rd), 1.37 (4th), 1.00 (5th), 0.82 (6th) and 0.73 (7th) – and a shorter final drive ratio of 2.82 was introduced; the Comfort (‘C’) setting was also omitted. Other hardware changes included a larger main radiator, ‘optimised’ power steering cooler, an additional transmission cooler and an oil cooler for the rear axle with an extraction-type fan. As a result of these changes, the CLK 63 AMG Black Series could accelerate from rest to 100 km/h in 4.3 seconds and had an electronically-limited top speed of 300 km/h.

For the CLK 63 AMG Black Series, front and rear track were increased by 75 mm and 66 mm respectively (to 1568 mm at the front and 1540 mm at the rear). The Black Series was fitted with AMG threaded sports suspension which enabled the driver to alter:

• the suspension level;
• compression and rebound stages of the shock absorbers;
• front-axle track and camber; and,
• rear-axle track.

Other suspension changes included newly developed spring links, wheel carriers, thrust arms, camber and torque struts, while strut braces were fitted in the engine compartment and boot for greater rigidity.

The CLK 63 AMG Black Series was fitted with lighter and wider 19-inch forged AMG alloy wheels (9.0J front and 9.5J rear) that were combined with 265/30 R19 front and 285/30 R19 rear Pirelli P Zero Corsa sports tyres. The Black Series was fitted with an upgraded braking package which consisted of 360 mm by 36 mm composite front brake discs with six-piston callipers and 330 mm by 26 mm rear discs with four-piston brake callipers; both front and rear discs were ventilated and perforated. For greater traction, a multi-plate locking differential was fitted as standard – it had a 30 per cent locking effect in over-run and 10 per cent under traction.

Inside, the CLK 63 AMG Black Series had bucket-type front seats – without side airbags – that were covered in nylon velour and featured embroidered silver AMG logos, while the rear seats were omitted; other details included a black headliner, carbon fibre trim for the centre console and inner door cladding, aluminium door handles. The Black Series was fitted with a 365 mm diameter steering wheel, 15 mm smaller than the standard wheel for the CLK 63 AMG.

To accommodate the increased track, the CLK 63 AMG Black Series had flared wheel arches that increased its width by 93 mm (to 1833 mm, excluding mirrors). Other visual cues for the Black Series included its unique front apron with large cooling intakes and lateral carbon-fibre outlets, rear apron diffuser fins and carbon-fibre bootlid spoiler.

Brochure

• Brochure: Mercedes C209 CLK 63 AMG Black (International) (March 2007)

Related links

• Specifications: Mercedes-Benz C209.II CLK 63 AMG (October 2006)
• Specifications: Mercedes-Benz C209.II CLK 63 AMG Black (November 2007)
• Wikipedia.org: Mercedes-Benz C209 CLK