In the early summer of 2005 the second generation of the CLK-Class underwent a comprehensive model refinement. To begin with, a line of three newly developed six-cylinder engines made the vehicle even more powerful and sportier: the new CLK 350 with standard seven-speed automatic transmission (200 kW/272 hp) relieved the previous CLK 320, exceeding it in power by 25 per cent and in torque by about 13 per cent. New was also the CLK 280, whose 170-kW (231-hp) V6 engine had even 36 per cent more power compared with the preceding CLK 240 and an increase in torque by 25 per cent.
Diesel engine fans would also experience more driving pleasure and dynamics in the CLK-Class from this point on. The new CLK 320 CDI with state-of-the-art diesel direct-injection engine was as exemplary in power development (165 kW/224 hp) and torque (510 newton metres with 7G‑TRONIC) as in fuel consumption (NEDC overall consumption): 7.5 to 7.7 litres per 100 kilometres - with six-speed manual transmission 7.2 to 7.3 litres per 100 kilometres. The proven four-cylinder diesel engine with 110 kW (150 hp) was now also available in the CLK Coupé; it required only 6.4 to 6.5 litres of fuel per 100 kilometres. In Germany, the Netherlands, Austria and Switzerland Mercedes‑Benz fitted the diesel models of the CLK-Class with particulate filters as a standard feature.
As of June 2005 Mercedes‑Benz upgraded the comprehensive standard safety equipment of all CLK models with newly developed, crash-responsive NECK-PRO head restraints. They optimised protection of the driver and front passenger in a rear-end collision: if the sensor system detected a rear-end collision with a defined severity of impact, it released pre-compressed springs inside the head restraints that in a fraction of a second moved the head restraints forwards by about 40 millimetres and upwards by 30 millimetres, in order to support the front-seat passengers' heads in due time. The front-seat passengers' heads were then duly supported and the risk of whiplash injuries reduced. After a NECK-PRO deployment the head restraints could be unlocked using the supplied tool and manually pushed back into their original positions. Effective immediately, the automatic tyre pressure loss warning system and ISOFIX child seat attachments were also standard on the CLK. Bi-xenon headlamps with active curve lights were optionally available.
The CLK Coupé's appearance also indicated its increase in power after the comprehensive model refinement: the newly designed front bumper with distinctive V-shape and larger air inlets as well as the modified radiator grille with three (instead of the previously four) louvres added up to a more dominant look. The characters of the two equipment lines were now also more clearly highlighted: in the ELEGANCE model the louvres of the radiator grille were silver-coloured, and black in the AVANTGARDE line.
Mercedes‑Benz consistently extended this differentiation to the side view. For example, the CLK-Class in the AVANTGARDE line now had silver-coloured 17-inch light-alloy wheels with a five‑double-spoke design as a standard feature, while the ELEGANCE line was distinguished by nine‑spoke light-alloy wheels (16 inches) painted sterling silver. Newly designed brilliant tail lamps with more pronounced horizontal structure supported the powerful design idiom of the CLK-Class. In the AVANTGARDE line the cover plates were dark-tinted.
With a great love of detail, Mercedes‑Benz designers had upgraded the interior of the CLK-Class and attended to even greater expression of the individuality of the lines. For example, new black seat covers made from a combination of ARTICO man-made leather and fabric were standard on the models of the AVANTGARDE line. Alternatively a new leather interior was available, with seats, door centre panels and rear side elements appearing in a contrasting colour. Available were basalt grey, pebble beige, tundra brown, flamenco red and cappuccino brown. Instead of the standard aluminium trim, black ash wood trim was also possible in the AVANTGARDE line. The roof liner of the AVANTGARDE line appeared in black. Also new was the instrument cluster of this equipment line. It was distinguished by a front cover of matte aluminium, white dials with special lettering and chrome rings on the round gauges.
The colour and material concept of the ELEGANCE line was also upgraded all round. A new fabric design in black or basalt grey, optionally a new leather interior in black, basalt grey or pebble beige, and new dark ash wood trim underscored the restrained elegance of the interior. For both lines the leather interior received a new grain with a higher-quality, softer character.
Mercedes‑Benz accommodated the desire of many customers for a sportier touch with two new equipment packages. They contained not only visual equipment features but also technical modifications for even greater vehicle dynamics. That's why the Sports package offered, besides 18-inch light-alloy wheels with a multi-spoke design, wide-base tyres in front of size 225/40 R 18 and 255/35 R 18 at the rear, chrome-plated tailpipe trim and an exhaust system with a special sporty sound for the four and six-cylinder petrol models, along with cross-drilled brake discs, brake callipers with Mercedes-Benz lettering and a sports suspension including a body lowered by 15 millimetres, among other items. In the interior there were multicontour seats in front for even better lateral support, steering-wheel shift buttons (with automatic transmission), sport pedals with an aluminium look and velour floor mats with silver-coloured edging.
On choosing the AMG Sports package, customers received additional features like AMG bodystyling with newly designed front apron, the AMG spoiler lip on the boot lid, the chrome-plated AMG exhaust dual tailpipe and floor mats with stitched AMG logo. Another special feature of the AMG Sports package was 18-inch light-alloy wheels painted in sterling silver with a five-spoke design. The tyre sizes were 225/40 R 18 at the front and 255/35 R 18 at the rear.
The 2006 Geneva Motor Show witnessed the première of the exclusive high-performance CLK 63 AMG Coupé, which thanks to its powerful 8-cylinder engine and elaborate suspension technology offered an especially fascinating driving experience. Under the bonnet of the CLK 63 AMG operated the AMG 6.3‑litre V8 engine: with a peak power output of 354 kW (481 hp) and a maximum torque of 630 newton metres, the CLK 63 AMG provided more power and torque than any other vehicle in this segment. A perfect companion to the dynamic power development was the AMG SPEEDSHIFT 7G‑TRONIC.
A new AMG sports suspension, new AMG light-alloy 18-inch wheels and exclusively dynamic standard equipment lent the high-performance model an even sportier character. The front axle moreover received a new AMG high-performance composite braking system.
A new front apron with more distinctive contours and side air outlets signalled the dynamic AMG bodystyling and underscored the CLK 63 AMG as a sporty top model combining dynamics and exclusivity. These properties were also reflected in the interior by a new ergonomic AMG sports steering wheel, AMG sports seats with multicontour function and exclusive nappa leather upholstery.
In summer 2006 the CLK 500 Coupé received a new V8 engine with 285 kW (388 hp). The 5.5‑litre V8 with a maximum torque of 530 newton metres (predecessor: 460 newton metres) made the CLK-Class outstanding in driving performance: the sprint from 0 to 100 km/h was completed in 5.2 seconds (predecessor: 5.9 seconds), the top speed was limited to 250 km/h. Despite the 26 per cent increase in power, the NEDC fuel consumption rate of 11.4 to 11.5 litres per 100 kilometres remained at the good level of the predecessor model.
A particular treat was the CLK 63 AMG Black Series - developed at the AMG Performance Studio. The fast two-seater V8 coupé was based on the Official F1TM Safety Car. Its AMG 6.3‑litre V8 engine uprated to 373 kW (507 hp) allowed acceleration in 4.3 seconds from 0 to 100 km/h - accompanied by the powerful AMG V8 sound from the new AMG sports exhaust system. Optimised for motor racing, the coupé had elaborate cooling measures ensuring maximum durability even under demanding conditions.
Power transmission, suspension and brakes were in no way inferior: the modified AMG SPEEDSHIFT 7G-TRONIC including shorter final-drive ratio ensured even greater responsiveness in all vehicle speed ranges. The newly developed AMG coil-over sports suspension allowed a personalised suspension set-up including adjustment of the ride height. A limited-slip rear-axle differential provided optimal traction, and the AMG high-performance braking system with larger composite-technology discs at the front axle allowed impressive deceleration. Astounding cornering speeds were guaranteed by the standard sports tyres of size 265/30 R 19 (front) and 285/30 R 19 (rear), mounted on especially lightweight 19-inch AMG forged wheels.
The CLK 63 AMG Black Series also looked like a close relative of the Official F1TM Safety Car. A new front apron with large cooling air inlets and lateral carbon-fibre outlets, flared wings as well as a rear apron with diffuser fins and active rear-axle cooling were unmistakable evidence of the carry-over from motorsport that had been part of the Mercedes‑Benz AMG philosophy for 40 years. The interior continued the uncompromising line. AMG sports bucket seats, AMG Performance steering wheel with oval rim and a diameter of 365 millimetres, carbon-fibre in the centre console, the AMG instrument cluster and interior door trim created the functional atmosphere of a genuine racing car.
The Sport Edition of the CLK Coupé, available from April 2007, made a new splash with its sporty look and outstanding equipment. Especially impressive were the 18-inch wheels with an exclusive six‑double-spoke design (225/40 R 18 at the front, 255/35 R 18 at the rear), and AMG bodystyling elements. Inside, the ergonomic AMG sport steering wheel with its excellent grip, sports pedals with an aluminium look and special velour floor mats especially governed the sporty and exclusive ambiance.
The design of the special model also included a front apron with distinctive contours as well as a rear apron and side sill panels characteristic of AMG models. In addition, the front axle had cross-drilled brake discs. The brake callipers of the Sport Edition models bore 'Mercedes-Benz' lettering.
Standard were the CLK special models Sport Edition with bi-xenon headlamps with dynamic headlamp range control, cornering light function with integrated fog lamps as well as a headlamp cleaning system. Active curve lights were also optionally available. Large chrome-plated tailpipe trim and a special rear silencer provided a sporty and lush engine sound.
The basis of the Sport Edition was the previous sporty, high-quality AVANTGARDE equipment line. The interior of automatic transmission vehicles featured an AMG sports steering wheel with perforated leather in the grip area and steering-wheel shift paddles for an even sportier flair. Depending on the engine version, a further technical highlight was available - the 7G‑TRONIC Sport seven-speed automatic transmission with shift times shortened by up to 30 per cent.
The sporty ambience underscored a black upholstery combination in high-quality ARTICO man-made leather, combined with fabric. A black leather interior was optionally available. Striking were also the sport pedals with an aluminium look and studs for a good grip as well as velour floor mats with silver-coloured looped edging. The special Mercedes‑Benz Sport Edition CLK models were available as coupés in six powerful engine variants, qualifying as the most economical models of their category.
The customer delivery of the 300,000th vehicle of the CLK-Class on 30 May 2007 marked an important milestone for the successful second generation of this 209 model series. Since the world première in May 2002, more than 200,000 CLK coupés and 100,000 CLK Convertibles (from May 2003) had been delivered. The most popular engine for the Coupé of the CLK-Class was the six-cylinder variant CLK 350, but the powerful and yet economical diesel engines were also in high demand. The most important sales markets of the sporty-dynamic coupés were Western Europe and the US. More than half of the customers chose the AVANTGARDE design and equipment line. The most popular special equipment included the Sports packages, light-alloy wheels and the innovative 7G‑TRONIC 7-speed automatic transmission.