Mercedes SLK class (R170)

The name "SLK" standards for "Sport", "Light" and "Compact", it also indicates this is a compact version of the much-loved SL sports car. Though based on a shortened C-class platform, its styling follows 90% of the SL's shape, just shorter, more compact and cute. This design successfully combines fashionable style with the traditional sophisticated image of Mercedes-Benz. 

The SLK was launched in 1996, the year roadster-booming period started. Judging by sales figure of 50,000 units annually, it has been a great success. However, more and more competitors emerged during the period, especially is Audi TT Roadster, which knocks right on the SLK. In contrast, the SLK becomes mechanically outdated and unrefined. Although the electric foldable hardtop is still an interesting and unique feature, the supercharged four-pot was criticized as rough, harsh and hate revving. It used C-class' recirculating ball steering, thus steering feel was uninspiring. 

Compare with rivals - we're talking about TT Roadster, the flawed BMW Z3 and Alfa Spider only, not Boxster or S2000 - the Mercedes has the least driver appeal. Why? look at the lazy-revving supercharged engine accompany with the lazy-driver-beloved 5-speed automatic, you'll know it was not designed by engineers who really love driving excitement. Maybe the marketing department has too much influence. Commercially that was quite correct, as most of the Mercedes' drivers, especially is in the important American market, prefer a relaxed driving style. To car journalists, the result is reversed. They always complain the SLK lack of driving fun. 

I'm not sure whether Mercedes have listened to such criticism, but at least a make-over in 2000 make the SLK more refined and slightly more agile. The dreadful 2.3 Kompressor (193hp) is still on offer, so is the 2.0 Kompressor (163hp) which serves the European Continent, but they are now topped by a really good engine - the company's existing 3199 c.c. 18-valve V6. As in E320, CLK320 etc., the power plant is extremely refined - smooth, free-revving and quiet - yet torquey at all speed. Under SLK320's bonnet, it is rated at 214 horsepower and 229 pound-feet. Moreover, the torque curve peaks from 3,000 to 4,600 rpm. 

In contrast, the 2.3-litre Kompressor engine is neither smooth, quiet nor musical. However, its Eaton supercharger provides stream of torque that is not far behind the V6. Like many supercharged engines, at light load, the supercharger is disengaged from the engine via an electromagnetic clutch for the benefit of engine response and fuel consumption. 2.0 Kompressor does not differs from 2.3 very much, just displaces less to be benefited from taxation regulations in some countries, especially Italy. 

Mercedes also improved the transmission. A new close-ratio six-speed manual is taken from the facelifted E-class, which should silent those complaining the SLK lack of a manual. However, majority will still choose the 5-speed automatic with Tiptronic-style manual mode. The superb auto box shifts smoothly and quickly. 

Chassis was also improved, but more like a response to safety and requirements for refinement. The front structure is slightly revised to provide better crash protection. Subframe is added to the front suspensions to filter out shock and vibration. The power steering is also tuned to give more direct feel, although it is actually lighter. 

All the changes are evolution rather than revolution, but the summation of them result in a SLK320 which is quicker, refiner and slightly more inspiring to handle than before. The good points remains unchanged, such as a stylish and elegant interior (although slightly retrimmed), then again the innovative electric foldable hardtop, which can be stored in the boot within 25 seconds. This make high speed cruising in autobahn become a lot quieter, as well as providing full weather protection. When the roof is up, there is also a big boot available, unlike other roadster. 

The above report was last updated on 17 Mar 2000. All Rights Reserved.


The hottest SLK shares a lot of common parts with C32 AMG, such as the 354 hp supercharged V6, the Speedshift 5-speed automatic, wheels and tyres. As it carries 65 kg less, it could be only quicker off the line than its 5-seat brother. Mercedes is talking about sub-five second to 60 mph, which is decisively quicker than Boxster S or just everybody else - until the arrival of 343 hp BMW M Roadster.  

There are some similarities between this SLK and M Roadster. Both of them are stiffly sprung and ride comparatively harsher than their sedan equivalents (C32 AMG and M3, respectively). Both of them steer in the way without inspiring their drivers, unlike their sedan equivalents. Both of them have a fire-breathing power plant overwhelming the chassis. They are modern hot-rod.  

In nearly all aspects, SLK32 AMG edges out the M Roadster, thanks to a newer chassis. "Newer" is just comparative, because the SLK is built on a C-class platform a whole generation lagging behind the new C32 AMG. And it still employs that uninspiring recirculating-ball steering. Nevertheless, the BMW is even older - it can be dated back to the 3-series of 2 generations ago, that is equivalent to the Jurassic 190E era in Mercedes' language.  

Anyway, our current class leader is the Boxster S, so the AMG SLK is still relatively dated. I mean the chassis, not the power plant which is wonderfully powerful and smooth. The Porsche rides better, balance better, steers with much more feel, corners fluently .... the Mercedes fight with understeer into corner, letting the ESP and traction control deal with wheel spin which occurs so easy compare with the Porsche. The chassis feels less rigid ... the cabin does not offer as generous room as the Boxster ... being priced 20% higher than its rival ... my choice is very clear. 

The above report was last updated on 22 Apr 2001. All Rights Reserved.


SLK230 Kompressor
Front-engined, Rwd
Front-engined, Rwd
Front-engined, Rwd
L / W / H / WB : 4010 / 1712 / 1265 / 2400 mm
Inline-4, dohc, 4v/cyl, 
V6, sohc, 3v/cyl, VVT,
twin-spark, variable intake, 
balancer shaft.
V6, sohc, 3v/cyl, VVT,  
twin-spark, supercharger.
2295 c.c.
3199 c.c.
3199 c.c.
193 hp
214 hp
354 hp
206 lbft
229 lbft
332 lbft
5A with manual mode
5A with manual mode
F: double wishbones; R: multi-link
F: 205/55 R16 
R: 225/50 R16
F: 225/45 ZR17 
R: 245/40 ZR17
1338 kg
1349 kg
1495 kg
Top speed
140 mph*
155 mph (limited)
0-60 mph
7.4 sec*
4.9 sec*
0-100 mph
20.0 sec*
11.2 sec*
* Tested by Autocar

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