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Mercedes-Benz SLK

Mercedes-Benz SLK Published: 20th Jan 2020 - 0 Comments - Be the first, contribute now!

Mercedes-Benz SLK
Mercedes-Benz SLK
Mercedes-Benz SLK
Mercedes-Benz SLK
Mercedes-Benz SLK
Mercedes-Benz SLK
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Why not own a...? Mercedes-Benz SLK

Mercedes has a thing about the sports car roofs. First there was the glorious Gullwing 190, followed by Pagoda perfection and then the radical SLK with its all metal electric ‘Vario’ roof. The idea itself wasn’t exactly new as this type of metal roof was popular with large American convertibles, but Mercedes made it more compact, more stylish and more appealing, words which sums the SLK up well.

This ‘baby SL’ has been around for almost a quarter of a century catering for an increasing number of enthusiasts who prefer modern classics, thanks to their better appointments and conveniences, together with 24/7 dependability. A good SLK gives you all this and for the price of a half respectable MGB!

Which model to buy

There’s essentially two generations to interest the classic enthusiast and broadly speaking the later Mk2 is perceived as being not so classical – in terms of styling at any rate – but is the better car all round.

Unlike the overseas markets, initially ‘our’ SLK came as just the 230K (the K being short for Kompressor, or supercharger) singleton mated to a four-speed automatic transmission. Four years later a mild facelift saw a new lower power entry-level model, the SLK 200K, alongside the new rangetopping SLK 320 V6, offering 163bhp and 218bhp respectively with ESP traction control becoming standard across the range.

Reprofi led bumpers, body-coloured side skirts and redesigned door mirrors which now incorporate the indicator repeaters are part of the facelift. A year later, the 32 AMG with 349bhp supercharged V6 is unleashed and the standard equipment includes 17-inch alloys, sports seats, cruise control plus a body styling kit. In 2002, the Limited Edition appears, graced with 7.5x17 alloys, black nappa leather and brushed aluminium interior trim. Both SLK 230K and SLK 320 special editions became available. Following on, two years later, the Special Edition has 16” alloys, grey or red nappa leather and brushed alloy interior detailing. Once again, the Special Edition is available in both 230K or 320K forms.

A new SLK débuts later that summer that’s bigger than the old model, with a roomier interior and a larger boot, a raft of new tech (including extra safety features) and a much stiffer bodyshell. Under the bonnet comes a choice of 1.8 or 3.5-litre petrol engines (SLK 200K or SLK 350), and there’s also a new high-performance variant, the SLK 55 AMG using a supercharged 5.5-litre V8. The four-cylinder and V6 engines now sport a six-speed manual as standard; a fi ve-speed auto is optional in the former, a seven-speed available in the latter.

A milder and easier to own SLK 280 joins the line up in 2005, with a 231bhp 3.0-litre V6 engine that’s plenty fast enough. A facelift for 2008 unveils a sportier nose plus more power for most engines and even more standard kit. Three years later an all-new SLK goes on sale taking the SLK to another level.

The difference in build quality between these two SLK generations is signifi cant. While there are some superb examples of the 1990’s R170 around, the chances of buying a ropey roadster are surprisingly high. That’s not the case for the Mk2, and while you’ll pay more for one of these later models, you won’t necessarily pay that much more (due to much less classic status?-ed) and the chances of being landed with a dud are that much lower.

Thanks to the difference in build quality between them, the R171 is likely to survive in higher numbers long term, yet the R170’s increasing rarity won’t necessarily make it that much more collectible some experts say. Mike Grimsby (www. told us “I no longer sell Mk1s because there are so few really good ones left. Any that I do fi nd tend to have had a lot of work done to them which in itself can create problems; you have to tread very carefully when buying a fi rst-generation SLK because of the likelihood of corrosion”.

Behind the wheel

Let’s get one thing clear – the SLK is no MX-5. Rather the Mercedes is a great all round sporty car rather than an out-and out sports car. Most came as an auto and only the 320K and the AMG possessed what enthusiasts will regard as being a sports car. But as a nice easy owning, affordable prestigious cabrio coupé any SLK is an act that’s hard to follow. Handling is trim, they are comfortable, cruise well and look and feel classy and feel much more solid than later Mercs – if not the German’s earlier classics.

Entry-level SLKs may have just 163bhp to play with but it’s ample for many, although the 230K offers 30bhp of extra urge just when and where you need it most, whether it’s for fast cruising or for a swift overtake. While some rely on a manual gearbox, most UK SLKs sport a four or fi ve-speed automatic transmission which becomes nicely responsive in ‘Sport’ mode and shifts ratios smoothly.

The SLK is based upon a shorter wheelbase C-Class saloon which gives the handling a sharper feel but, shorn or rack and pinion steering, it’s not exactly razor sharp to pilot. Compensation comes in a very good ride and as you expect with a modern, anti-lock brakes with discs all round ensure there’s superb stopping power under foot.

The 2004 relaunch makes for a superior SLK in every area but especially the new really strong engines although the styling both inside and out is not as distinctive. From a classic perspective they’re also too new – if this matters to you.

It comes as no surprise that with the roof up the refinement is on a par with a C-Class saloon although even with the top down and at motorway speeds it’s still possible to converse comfortably and in great comfort. That novel, roof, when it’s working as it should, is brilliant and provides all year round open top motoring at the touch of a button.

No wonder SLKs are so popular with buyers but on the other hand their sheer numbers makes the SLK debatable as a ‘real’ classic because not every owner is a true blue enthusiast. Instead, the SLK makes a good classical daily driver to complement your real classic. On the other hand, with the car approaching 25 years old, the M-B owners’ club now hosts a dedicated SLK day event so who’s to say?

Making one better

There’s no shortage of SLK upgrades but the majority are cosmetic, aimed at making your Merc stand out from the crowd – if that’s what you want. With even the weediest SLK (the 200K) capable of 138mph and 0-62mph (100km) in a lively 8.2 seconds there’s probably no real need for performance upgrades, and if you do want more go it’s more logical to track down a bigger engined model. While there’s little stop watch difference in performance between the 230K and 320K, the latter is smoother and offers more low-down torque. Tuning methods centre upon a sportier exhaust, a ECU performance chip and a smaller pulley to make the supercharger spin faster before delving in the bowels of the engine, and at least these mods are reversible.

There’s a goodly range of suspension and brake enhancements and it’s here where the money is better spent although only after ensuring that the car is up to spec so there’s no worn bushes and such like to spoil things and a good set of proper quality tyres will improve the roadholding no end. If you need service replacements then here’s an ideal and cost effective opportunity to ring the changes.

The standard lights aren’t brilliant in all senses. For all models there’s a better, brighter xenon light conversion for £164 that makes a big difference and a worthy uprate if you intend to use yours as a daily driver.

Maintenance matters

Being Class-based the SLK is a very easy modern classic to own and run with plenty of independent specialists around to undercut the main dealers and contain costs – the same goes for aftermarket parts – see box out to the right on this page as evidence.

As you’d expect, being a Mercedes, the build is better than the herd but don’t think that the C-Class is carved from granite likes the Mercs of old because they are not; cars from the 1990s being disappointingly rot prone Happily, the roof mechanism while being pretty complicated should prove reliable in service. However, there are various sensors which are known to play up if the car isn’t used regularly, so put the roof up and down a few times every week to make sure all is well. The hydraulic oil should also be replaced every 10 years or so, and it’s worth swapping the pump relay (under a cover on the right-hand side of the boot) as a matter of course periodically, as they fail.

If you are considering buying an SLK you must insist that the hood is operated to your satisfaction before purchasing as involved repairs can outweigh the real world worth of the majority of early R170 SLKs.

Mum’s the word with this SLK

Pauline Dredge has owned her SLK 230K auto for 10 years. She comments: “I previously owned an MGF which was great fun but the Mercedes was too good an opportunity to miss. A one-owner low-mileage car, it’s in another league after the MG as it feels so much stronger and has a lot more performance. It’s also more usable than you might expect; I’ve been away with a friend for a week and it’s taken me to France on several occasions. The folding hard top means it’s usable in the winter, but it’s best left in the garage in icy conditions. Comfortable and easy to drive, the SLK is economical and has so far been completely reliable, although I’ve had to have a couple of rust spots attended to. By using an independent specialist (Mike Teague, 01905 353353) the running costs are less than half of what they’d be if I stuck with the main dealer”.

Finding that special SLK


Surprisingly for a modern rot can be a real issue with C-Classes including the SLK, so check the suspension arms and brake pipes for rust. If these have corroded there will be much worse hidden away. Inspect the wheelarches, sills, boot lid and number plate surrounds, the area around the rear number plate light, as well as the fuel filler flap. The leading edge of the bonnet is also prone. Also front wings can also rust quite badly; usually around the wheelarch and where it butts up to the wraparound bumper, so has it been repaired already?


The four-cylinder engines are known to be robust and will rack up 200,000 miles quite happily if looked after, although head gasket failure is quite likely in the form of weeping. The supercharger bearings can eventually fail, leading to rattling on tickover. The blower will continue to work merrily but it’ll get noisy; reconditioned superchargers cost around £500. The V6 is also a toughie but air mass sensors fail.

Running gear

Some SLKs wear a manual gearbox, but most UK cars are automatics. Manual gearboxes have a following but buyers tend to prefer the self shifters and the SLK32 AMG came in auto form only. Six-speed manuals can be problematic, make sure the changes are slick; this transmission can fail but there again the electrics on the autos can also play up.


The charging system isn’t foolproof. The voltage regulator on the alternator gives up, the heater resistor (easily and cheaply replaced), boot lights and the brake light switches are fallible plus the rear light circuit boards can melt. Also the alarm horn can sound continuously once water has got into the workings – many owners just disconnect it making car alarmless.


Drive a few to set a datum, avoid blinged cars. Joining the owners club is money well spent for the benefits it brings.

The car’s timeline


SLK arrives in the UK. Based upon four-cylinder C230K (supercharged) saloon it comes only with automatic transmission with one trim level.


Entry model SLK200 and SLK320 expands range; former uses 163bhp engine but latter employs 3.2-litre V6 for 218bhp. ESP traction control and six-speed autobox feature across all ranges. Facelift also sees tidied up looks with new bumper and body-coloured side skirting.


AMG 3.2 becomes range flagship. Twin spark-plug engine delivers 349bhp fed via a special gearbox; only 263 official RHD UK cars were offered.


Limited Edition reaches showrooms sporting 7.5x17inch sports alloys, black nappa leather interior highlighted by brushed alloy trim detailing.


Special Edition launched to mop up models with 16inch wheels, grey or red nappa trim and the previous brushed aluminium detailing. That summer, the new (R171) SLK replaces original R170 with new look, longer wheelbase, seven-speed transmissions and added safety features.


Facelift sees refreshed look, new engine line up. Car later becomes part of the general SL range.

What to pay

There are good R170s to be had, but you should expect to pay at least £3000. Buy one for half price – they are about – and chances are that you’ll end up spending much more in the long run. Really good R171s command £4000 minimum while the very best low-milers with a few factory-fitted extras can sell for as much as £8000. Good R171s start at £5000 for a ’04 SLK 200. Expect to pay upwards of £6000 for a nice V6 with the very best going up to £12,000; the point at which third-generation SLKs start. Just 271 AMGs were sold here. They don’t come up for sale very often but if you’re lucky enough to track one down you should expect to pay between £10,000 and £12,000. Second-generation AMG editions are much more plentiful but you’ll be doing well to own one for less than £12,000.

Here’s six of the best reasons to buy one

  • Shrunken SL character and style
  • Superb all weather roof
  • Great value for money
  • Wide selection on the market
  • Specialist for spares and repairs
  • As easy to own as a C-Class

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