Fast Facts

• Best model: 300SL
• Worst model: 450SL
• Budget buy: 380SL
• OK for unleaded?: Yes
• Will it fit in the garage? (mm): L4630x W1791mm
• Spares situation: Excellent
• DIY ease?: Good aside from electrics
• Club support: Good
• Appreciating asset?: Values are rising quickly
• Good buy or good-bye?: One of the most usable two-seaters you can buy, but still a sure-fire investment opportunity if you buy the right car

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Long running replacement for iconic Pagoda. More suave GT than serious sportster, but still a car admired for its style and engineering. Price rising yet still strong value. Superb back up for clubs, specialists – and dealer

Mercedes used to sell its products using the strapline “engineered like no other car” and it was no idle boast. Developed to a level far beyond what most of its rivals could manage, Mercedes’ products were stronger, safer, longer-lived and more usable than anything else available. The SL has always been a case in point because while these stylish two-seaters have never been the last word in scalpelsharp handling, they have always been hugely desirable for the quality of their engineering and their usability.

While the SL has always been one of those reassuringly expensive cars, available only to the relatively wealthy, they’ve also usually been built in large enough numbers to become far more affordable after a few years. That was the case with the R107 SL, launched in 1971 and produced right the way through to 1989. However, the era of the bargain R107 has now passed and you’ll need relatively deep pockets to acquire a good one. But buy well and you’ll find plenty of investment potential – but buy badly and you could lose a packet. And it’s a lot easier to buy badly than you might think.

History

1952 The first SL is launched by Mercedes – the legendary 300SL ‘Gullwing’ racer. At first it’s a competition car only but within two years there’s a road-going version which is followed by a Roadster edition in 1957. The more affordable 190SL had arrived in 1955, offered in roadster form.

1963 A more affordable SL arrives in the form of the W113 ‘Pagoda’. It’s still an exclusive car though, but it’s made in significantly greater quantities than any of its predecessors.

1971 The R107 goes on sale and would remain in production for a whopping 18 years, making it Mercedes’ longest-lived model ever, aside from the G-Wagen. At launch there’s just a 3.5-litre V8 for European markets, while American buyers get a 4.5-litre V8, both models badged 350SL running on new 97ins S-Classderived chassis and suspension.

1973 European buyers are now able to choose the mighty 4.5-litre engine, in the 450SL the flagship that cost the price of more than two Triumph Stags!

1974 The oil crisis hit everybody, including Mercedes who quickly brought out an ‘economy’ six-cylinder 280SL, with a focus more on mile per gallon than out-and-out performance from its sedate but smooth 185bhp engine.

1977 Power is soon back on the menu with the 450SLC 5.0. A stretched 2+2 SL hard-top coupé, the SLC, arrived alongside the SL soon after launch but it wouldn’t make much of an impact. It can make a great left-field buy now though.

1980 A range-wide facelift brings a series of tweaks and improvements, the most significant of which is the arrival of the 380SL and 500SL, with the all-alloy V8 that was introduced in the SLC, which after a decade in production was killed off in 1981, to be superseded by the larger, swisher S-Class-based SEC.

1986 A further facelift to the SL brings a front airdam to enhance economy and high speed stability for all models and a new much improved six-cylinder model, the 300SL is introduced. The mid-range car is now the 420SL while, for US buyers, a 560SL is available. Also, a four-speed auto is now fitted. These models would remain in production until the R107’s demise in 1989, when it was superseded by the R129. After 18 years of production, 237,287 examples were made.

Driving and press comments

A big engine, a rag top and two (or 2+2) seats might be the perfect recipe for a sports car, but the SL is much more of a grand tourer. The car evolved over the years, with engines ranging from 2.8 to 5.6 litres and either six or eight cylinders, but no SL can be labelled as truly sporting.

The SL received surprisingly few column inches in the UK press during its lifetime but when Motor tested one of the first 350SLs in 1971 it was impressed by the ease of driving and the build quality. The magazine wrote: “On the road the cars are superb; they are not very fast off the mark but for out and out speed the power is enough for a 130mph maximum… What is impressive straight away is the solidity of construction. Whatever the surface the car chunters across the top with only a remote flutter of the wheel (scarcely audible) – no shakes, no rattles and no loss of stability either on the straight or on bumpy corners. There was no wind noise either and just the contented hum of the engine to keep you in touch with the outside world… And now for the most impressive feature – the roadholding on wet roads. These weren’t just good clean watered ones, but the grip was so good that one could really forget about the rain and go as fast as more sane mortals do in the dry”.

Even more impressively, when Motor first encountered the SL in 1971, the test cars were fitted with an electronic anti-lock braking system which worked superbly, pulsing the brakes at 15 times each second. There’s no mention of whether or not the system was offered on showroom cars; it was mentioned almost in passing within the review. We don’t think customers cars could be ordered with it at this point; we reckon the S-Class would be the first car available with the technology, several years later.

More Sporting Than Touring headlined Autocar’s August ’71 test but the testers praised its handling where “The tendency to tail swing and transition to oversteer which used to be experienced with previous SLs, has been eliminated.” It concluded that, overall, despite it feeling rather fussy and noisy, and not to say very expensive, the 350SL was “a very safe, well built car.”

A further test in ’72 had the weekly comment, “The 350SL has lost some of the driver enjoyment which used to be associated with the [old Pagoda] 280SL but it makes up for this in terms of extra safety. Not even the wildest driver could get into trouble with it and still blame the car.”

In the early 80s, with the car really in its twilight years, Car magazine tested a 280 variant and reckoned out of the entire range, power per pound, it was the best buy at just under £17,000. Criticising lowly gearing (even with the manual five-speed model) and a general rather old fashioned feel, it said the SL was ideal for “cruising sedately yet quickly” although said the “chassis won’t be remembered for its leech-like road-holding.”

The monthly rather grew to like the car however because it added: “If you’re being polite about this Mercedes SL, you’d call it a traditional car; it feels like an old one… but doesn’t make it a bad one.”

In modern terms, the SL feels woolly and fussy due to low gearing that – in Autocar’s hands – resulted in a fearful 14.7mpg but more classical driving should see nearer 20mpg. Like all good Mercs, it feels as solid as rock and yet a comfortable and spacious one – as it should be, given its overall size, although the rear seats are quite hopeless, as ‘Kiddie corals’ Car sarcastically stated in its road test! But they have a point…

Values and marketplace

There’s a wide spread of values where SLs are concerned because there are so many variables to consider. Sam Bailey runs the Worcestershire-based SL Shop. As Europe’s (and probably the world’s) biggest R107 specialist, Bailey buys and sells more of these cars than anybody – 900 so far. He comments: “Post-1986 R107s are worth around 30 per cent more than earlier models while buyers will pay a premium for an SL with a manual gearbox as they’re so rare. Left-hand drive SLs are also worth up to a third more as these cars have such an enthusiastic following in Europe – but only cars originally sold there carry the premium. US imports aren’t so well loved, although the 560SL does have a market as for some it’s the ultimate R107, with its 5.6-litre V8”.

Bailey continues: “We rarely sell a car for under £30,000, although R107s can be picked up for much less than this. Expect to pay at least £15,000 for something that won’t need significant expenditure in the near future; this nets an average pre-1986 car or a post-1986 example that needs work. But realistically you need to spend £25,000-£40,000 to get something really nice – or £50,000-£60,000 if it’s a low-mileage car with few owners. We recently sold a car with 4200 miles on the clock for £88,000 and many of our customers are already spending tens of thousands of pounds with us restoring their SLs, so it’s safe to say that the R107’s time has come”.

Bailey admits that the SL Shop operates at the top end of the market, and that cheaper cars are available, but it’s very easy to get your fingers burned. He says: “We used to sell a lot of entry-level R107s but it became clear that buying a cheap SL then making it good always costs more than just buying a really superb car in the first place. Now we buy and sell fewer cars and our focus is exclusively on very, very good examples – yet we still typically have to spend a week preparing the car before it’s ready for sale. If you buy a tired SL it’ll probably still be reliable and okay to drive. But buy one that’s properly sorted, with smooth gearshifts, taut suspension, precise steering and strong brakes and you’ll get the genuine R107 experience. All those small differences add up, so while an average SL is a nice car, a top-calibre example is on another planet”.

Left-hand drive doesn’t seem to make a car worth less as long as it’s to European spec, but US spec, with their ugly big bumpers and emissions-strangled engines, are worth less than equivalent UK cars.

Improvements

As the only company in the UK to focus almost exclusively on the R107, nobody is better placed to come up with a package of upgrades than the Worcestershire-based SL Shop. Launched at the start of this year, the company’s SportLine uses a 300SL as its start point, then comprehensively re-engineers it to come up with something truly special.

Company founder Sam Bailey says: “The SportLine project came about because our customers are spending significant sums of money with us when restoring their SLs, and some were asking for upgrades to be incorporated. They want a more sporting SL for the occasional track day or to enjoy a spirited drive out. With these cars so over-engineered we knew the potential was there to create something special, so we worked with the best companies we could find to develop the best engine, transmission, exhaust, suspension and braking systems. I do some circuit racing and have built up a network of contacts perfectly placed to work with us; the SL Shop has also built up lots of contacts around the world who can help with manufacturing uprated parts”.

In typical SL Shop fashion, every aspect of the R107 has been addressed, right down to the interior trim. Not only are there SportLine design details throughout the cabin (such as white-dial instrumentation), but improved seats have been developed which offer more support during cornering. But of course it’s the mechanical changes that are at the heart of the SportLine. The suspension has been lowered by 80mm, a bespoke stainless steel exhaust created, the injection system overhauled and a limitedslip diff developed.

The throttle linkage has been re-engineered for improved throttle response, the cam profile revised and a modern coil pack fitted for a more precise spark. The result is a peak power output of 255bhp – enough to give 0-60mph in just under six secs and maxes over 160mph.

When launched, the plan was to offer the SportLine only as a complete package as part of a ground-up restoration. But with the SL Shop’s workshops already booked up for the next three years and not everybody wanting their R107 restoration to incorporate changes from the original specification, it seemed a shame to limit who could take advantage of all the development work undertaken. As a result, a SportLine kit is available which can be fitted to a customer’s 300SL without the need for a complete overhaul.

Also, recognising that not everybody will want the whole kit, which costs around £20,000, customers will soon be able to pick and choose which parts they want. As a result, they’ll be able to select from items such as recalibrated springs and dampers, the more free-flowing exhaust or perhaps just some of the interior parts.

A six-speed manual-gearbox conversion is also available for the 300SL, for £6000, while engine upgrades are offered on a bespoke basis, including items such as bigger injectors, an electronic fuel injection conversion with an ECU, reworked cylinder head and reprofiled camshaft.

So far only a 300SL-based six-cylinder model has been created, but the SL Shop is already working on a 500SL-based SportLine. With the six-cylinder model offering the same power as a standard V8, it gives the best of all worlds as the smaller engine is lighter which improves the handling. But another 100bhp can easily and reliably be coaxed from the V8, which should make the next edition a seriously enticing prospect.

Also on the horizon is a SportLine R with a supercharged or turbocharged engine and currently in the paint shop is a SportLine racer which the SL Shop will be campaigning throughout 2017. We’ll bring you all of the latest developments as soon as we can. For more information log on to http://www.107sportline.com

More affordable mods from the aftermarket includes uprated springs and dampers for not much more than £500 with EBC brakes for similar amounts; for many this will satisfy the majority of drivers and cost-effective if replacements are needed anyway. The SL Shop markets a limited slip differential for a little over £1000 (plus fitting) to entice that swing axle to mend its ways but in all honesty, apart from the SL Shop’s fabulous SportLine upgrade kits, most owners like to keep them pretty standard and we’d certainly give garish customised SL the widest of berths…

Three Of A Kind

Mercedes R129

The much awaited replacement to the R107, this model is far more complex and sophisticated, meaning spares and repairs bills are considerably higher plus this technological tour de force isn’t as well built compounding issues. On the other hand, these mercy are cheap-as-chips plus are magnificent tourers as well as sharper drives than R107s. V8s are best but the six-cylinder models are okay although the engine can give problems.

Triumph Stag

Hailed as the ‘British SL’ when introduced a year before the R107 débuted, a good Stag is a delightful tourer now its infamous snags have been ironed out. Prices trail the SL by truly handsome margins but bear in mind that you can also buy a much later German offering that’s inherently of better quality. Unless dirt cheap or particularly good, avoid alien-engined Stags – the smart money now goes on originality.

Jaguar XJ-S

The XJ-S only became the true convertible it should have been in the 1990s; previously there was an ungainly-looking SC cabrio which can be quite sought after when the mood takes enthusiasts. A much sportier yet comfier car than the SL, but durability and reliability can’t hold a candle to the German. AJ6-engined (six-cylinder) cars best all-rounders and buy now as XJ-S prices are starting to seriously rise for good ones.