Car reviews - Mercedes-Benz - SLK-class - convertible range
23 Aug 2011
MERCEDES-BENZ’S SLK retractable hard-top convertible has been redesigned, overhauled and repriced $10,000 below the previous version to more effectively battle BMW’s Z4 and the Audi TT in the compact two-seater roadster stakes.
Kicking off from $82,900 (plus on-road costs) for the new entry-level SLK200 auto, the R172 series brings more aggressive style, a sharper drive and significantly more efficient direct-injection drivetrain offerings.
In contrast, the previous base SLK200K started at $91,450 for the special-order six-speed manual model, or $94,837 if the massively more popular automatic is considered, while the cheapest TT Roadster and Z4 are the respective $80,814 2.0 TFSI S-tronic quattro and $86,200 sDrive23i manual (or $2300 more for the auto).
At launch, a $118,900 SLK350 is also on hand, with the SLK250 mid-ranger (slotting in the mid-$90,000 bracket) and range-topping 310kW/540Nm SLK55 AMG arriving from the first quarter of 2012.
Although Mercedes insists the latest SLK is completely new, it has been reported in Europe that only about 70 per cent of the vehicle is actually different, perhaps helping to explain the newcomer’s sharper pricing.
Yet fresh standard features abound. These include adaptive brake lights, sun-reflecting leather trim, advanced driving aids such as Attention Assist, Pre-Safe, tyre pressure monitors, Parktronic parking guidance, improved telematics and connectivity, anti-whiplash headrests, an electric park brake, a boot with a reversible floor, LED tail-lights, daytime running lights and head airbags in the doors.
Buyers can now also opt for a new ambient lighting package, AMG Sports Package, illuminated doorsills, internet access, radar-controlled cruise control, various suspension enhancements, keyless entry/start, Nappa leather upholstery, improved night-time lighting and a trio of roof options.
With the original, W202 C-class sedan-derived R170 SLK credited with reviving the folding hard-top craze back in 1996, and the second-generation version ushering in the ‘AirScarf’ neck-and-shoulder heating option, the main innovation the R172 introduces is a “panoramic Vario-roof with Magic Sky Control” – not an LSD trip, but a glass roof with an automatic tinting/sun block out system courtesy of an electrical voltage through some particles in the structure.
Adding $4550 to the price, it is in lieu of the standard body-coloured roof and $1750 tinted polycarbonate transparent roof.
Another fresh idea is a pivoting draught-stop – transparent Perspex sections that attach to the rollover bars immediately behind the seats, allowing them to be turned to the centre of the cabin “to tame turbulent airflow” – and then disappear “almost invisibly” back behind the bars.
Both the SLK200 BlueEfficiency (BE) and SLK250 BE employ a variation of Mercedes’ new 1.8-litre turbocharged direct-injection twin-cam 16-valve four-cylinder BE petrol unit.
Delivering 135kW of power at 5250rpm and 270Nm of torque from 1800 to 4600rpm, the SLK200 sprints to 100km/h in 7.3 seconds on the way to a speed-limited 210km/h.
Australian performance statistics for the 150kW/310Nm SLK250 are yet to be finalised.
Meanwhile, the SLK350 BE packs a 3.5-litre petrol V6 with direct-injection, Piezo injectors and multi-spark ignition to help direct 225kW at 6500 and 370Nm from 3500 to 5250rpm to the rear wheels, helping it to hit 100km/h from standstill in 5.6 seconds on its way to a restricted 210km/h.
On the green side of the ledger, the smaller engine returns 6.9 litres per 100km and emits 161 grams per kilometre of carbon dioxide emissions, against its more powerful V6 sibling’s 8.3L/100km and 194g/km respectively.
All three use Mercedes’ 7G-Tronic automatic transmission, with all models boasting the enhanced ‘Plus’ gearbox development with decreased torque converter slip, reduced internal losses, improved noise and vibration measures, lengthened service intervals, and up to a seven per cent cut in fuel consumption compared to the older 7G gearbox.
Another mechanical innovation that aids efficiency and cuts consumption/emissions is an adjustable radiator shutter, for variably controlled airflow that improves drag, speeds up engine warming and heater performance – a vital element in a drop-top.
As GoAuto has reported, no diesel version is intended for local consumption at this stage, although the Australian subsidiary said rising fuel prices may see this situation change further down the line.
Built off the same 2430mm wheelbase as before, but with wider tracks, the R172 measures up at 4134mm long (up 31mm), 1810mm wide (up 33mm) and 1301mm high.
Boot space varies from 225 litres to a golf-bag friendly 335 litres, depending on whether the folding hard-top is in situ. Mercedes claims it takes less than 20 seconds to perform its electrically powered acrobatics.
The new SLK retains the classic roadster long-bonnet/short boot lines of its predecessors, but this time visually infuses the masculine lines of the flagship SLS gullwing supercar within its character.
Among the changes are a more protruding and upright radiator grille, squarer headlights (with new-to-the-series LED tech), and more defined angles throughout the body.
Aluminium is used for the bonnet and mudguards for improved weight distribution, while torsional rigidity improves throughout the vehicle, despite the bodyshell shedding 13kg. Kerb weights range from 1470kg to 1540kg.
Despite the larger frontal area, the SLK’s aerodynamic drag coefficient drops from 0.32 to 0.30Cd, aided by cleaner and tauter lines and finer attention to detail under the vehicle.
Again based on a development of a heavily modified C-class chassis, the R172 is underpinned by independent multi-link front and rear suspension.
Two suspension tunes are available for now – a Sports set-up with steel springs and dampers, and a Dynamic Handling Package using an electronically controlled, fully automatic damping system, for a wider breadth of comfort and driving pleasure, according to Mercedes.
The latter also includes Torque Vectoring Brakes, which the company explains assists stability through tight bends by producing a defined rotational movement about the vertical axis in milliseconds through selective brake actuation at the rear wheels.
Other driver-assist tech includes a drowsiness detection system, called Attention Assist, the anticipatory protection system dubbed Pre-Safe, and Pre-Safe Brake, which applies the brakes autonomously in the event of an impending rear-end collision.
These are on top of the ESC electronic stability control, ABS anti-lock brakes and Brake Assist items that Mercedes helped to pioneer over the last few decades.
Options include Distronic Plus proximity control that applies the brakes to standstill and back up to speed again according to the traffic conditions ahead using radar-guided cruise control, as well as the Intelligent Light system that brings cornering lights, country and motorway modes, an active light function and enhanced foglights, all again working depending on prevailing conditions.
Steering is via a hydraulically assisted ‘Direct Steer’ rack and pinion system, a variable ratio set-up that reduces parking effort while maintaining sharpness and stability at higher velocities. A solenoid valve also varies the amount of pressure according to speed, saving unnecessary power losses and so improving fuel efficiency.
Four-wheel disc brakes prevail, with 295/300mm front/rear on the SLK200 and 344/300mm items reserved for the SLK350. An electric park brake makes its debut in this series as well.
Engineered to achieve a maximum Euro NCAP crash test rating, the R172 now includes improved crash sensors for rollover hoop deployment, as well as better pedestrian-impact bumpers and a bonnet that springs up by 85mm to lessen body trauma from hard engine-bay components.
A new door-mounted headbag item for lateral head-impact area protection has been fitted, along with an additional thorax airbag in the seat backrest for improved side-impact safety, and Neck-Pro anti-whiplash head restraints.
The two-person cabin has attracted palpably higher quality materials, Mercedes says, to help up the refinement ambience and feel-good factor.
Brushed aluminium predominates, although wood trim is available, while the SLS influences continue inside with a quartet of galvanised air outlets. Retro fans can order an analogue clock in the upper-dash area, a la Maserati (or Mitsubishi TR Magna), for $510.
In-car storage capacity rises, with a 6.4-litre glovebox, as well as three compartments in the centre console.
Also of interest may be the improved telematics and telephony as part of the company’s radio, media and entertainment systems. Assisted by a menu controller and large colour display (where fitted), they conform to better functionality and ergonomic requirements.
Audio 20 is standard SLK200 fare, while the Comand Online in the SLK350 includes internet, DVD, Suna real-time Traffic management info, an SD card slot, and advanced 3D satellite-navigation. Linguatronic voice activation is also available.
Buyers can choose an AMG Body Styling package that adds a bodykit with spoilers and skirts, as well as darkened headlights and tail-lights, different cabin trim and seat stitching, AMG-branded chequered instrument markings, and lowered sports suspension with stiffer springs and dampers, special 18-inch alloys on lower-profile tyres, and a brake upgrade consisting of perforated 344mm front discs. An acoustically enhanced exhaust is also fitted on the SLK200/250 with this option.
According to a Mercedes-Benz spokesman, the aggressive entry pricing, combined with range-wide availability of desirable options such as the AMG kits, will broaden the new SLK’s appeal with buyers who may not have considered the series before.
“It will really put the cat among the pigeons, especially as customers can spec their cars up to look like an SLK AMG for about the same price as the old base car,” he said.
To date over 500,000 SLKs have been sold since production commenced in 1996.
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