Long running SL that mixes prestige with pragmatism and practicality although it’s more a tourer than sports car. Prices are rising but still good value and spares and repairs pose no problems. A classic that you can justify with your head as much as your heart

If the MX-5 is the new MGB, then what does that make the Mercedes R107 – the modern successor to old XK Jaguar? That’s not as silly as it sounds, as there are surprising parallels between the two. Both are cultured cruisers of the old fashioned kind, albeit generations apart, that have survived the fashion wars well, and come out as the winners by oozing good taste and dignity.

Where the German scores over Coventry Cat is in the sheer numbers still available, the robustness of the design (made the way Mercs should be) and excellent parts supply, which even includes the factory. Whereas the little Mazda is a 1990s design, harking back to the swinging 60s, the SL is the last of the traditional sports GTs, remaining in production from 1971 right up to 1990 – so it’s a classic but also one that’s ‘youngish’ – classical rather than classic you might say.

Small wonder, then, that SLs are becoming increasingly popular purchases, appealing to a broad buying base, yet they remain good value. However, there’s also a lot of dross out there, with only price on their side, so you need to take ultra care when buying.

HISTORY

1952 The SL bloodline started with the radical 300SL ‘Gullwing’ racer of 1952 with a road going model available by 1954. The hugely coveted W113 SL, better known perhaps as the Pagoda, followed which lasted until 1971. R107 SL is launched that year, and became one of the company’s longest servants, lasting almost 20 years in production. It was fairly similar to the early car in its make up but boasted a much improved rear suspension layout. Initially available in cabrio and hard-topped guises, there was just a 3.5-litre V8 for European markets, while American buyers got a 4.5-litre V8, yet both models were badged 350SL.

1973 European buyers could now get their hands on that larger engine in the new 450SL. This was the time when owning a Mercedes showed that you had serious money.

When launched the SL cost from a smidgen under £6000 which would have bought almost three Triumph Stags, but this don’t stop sales! Import duties really hiked the price of foreign cars and an SL was much dearer than an E-type (£2979), a few hundred more than a Jensen Interceptor (£5874), while just £500 extra could have got a well-heeled buyer a DBS6.

1974 The oil crisis that year led to Mercedes thinking more down market by offering the economy special 280SL. This six pot model packed 185bhp but was still an ample performer.  1980 Now coming up to its tenth year, an extensive-wide facelift in brought some welcome upgrades to refresh the aging line up, the most significant being the arrival of the 380SL and 500SL models, boasting the all-alloy V8 that was introduced in the SLC – a model which died in 1981, incidentally. Amazingly, this V8 didn’t last long because, for 1982, a new unit of similar size liberating 10 per cent more economy for just a slight power loss was introduced. Around this time the 500SL benefitted from revised gearing to improve high speed cruising.

1985 The 380 model now becomes the 420 thanks to an engine stretch, providing a claimed 218bhp. All are autos, but now the widely praised Mercedes four-speed unit is fitted. Also that year the 560 joined the line-up. Externally, a front air dam is now fitted to improve aerodynamics.

After the thick end of two decades in production, 237,287 examples of the R107 SL were made – so there are plenty of them to go round. And let’s not overlook the SLCs either! Essentially these are SLs but with a 14inch longer wheelbase to enable 2+2 accommodation. There’s a typical 100lb weight penalty across the ranges and arguably less balanced looks which makes them less popular and so even greater value for money. The 450SLC 5.0 is the best of the lot, if you can afford to run one.

DRIVING ANDPRESS COMMENTS

Even the most ardent SL fan will admit that this Mercedes is no sports car. The name SL may be short for Sport Light, but this is an old school Merc and these cars are better suited to touring than tearing around. Softly sprung and equipped with an antiquated steering box, handling is typically 1970s and it hardly improved over the decades, even though the car was fairly successful in rallying.

Another reason for the leisurely characteristics is because the vast majority come as autos as only a select line up of manuals, four-and five-speed, were available. But manual Mercs of that era aren’t favoured, not least in part due to the sloppy gearchange, some ill-chosen ratios and the foot-operated handbrake that meant you were always yearning for a third leg to press all the pedals at once!

Straight line pace isn’t bad for such a heavyweight of more than 1500kg. Expect a 280 to have the same performance as an average repmobile off the lights, while the V8s offer GTi-like pace, particularly the 420, 500 and 560s, although economy isn’t too good on any version.

Normal driving will perhaps coax around 21-22mpg, although this can seriously dip to the mid-teens on hard driven V8s. When Autocar tested a 350SL in 1971 it achieved 60 in just under ten seconds and the V8 fairly gulped the four-star down at 15mpg, not helped by rather low gearing for a V8. The smaller engined 280 will be better but don’t expect anything much over 20mpg from any car – a case for an LPG conversion perhaps?

The cabin is hard wearing, logical but never plush and, despite their sizes, the SL and to a much lesser extent the SLC aren’t over roomy but luggage space is generous on all. Incidentally, optional rear seats were available on the SL as an option or can be retro fitted, but even toddlers will complain over the lack of space in the back!

Compared to a Triumph Stag, the Merc feels tougher and better engineered and, when the SL arrived in the UK, Autocar’s test of the big V8 350 model judged that it was more touring than sporting, but praised its handling stating, “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.”

In the early 80s, with the car well and truly in its twilight years, Car magazine tested a 280 variant and reckoned, power per pound, it was the best buy at just under £17,000. Criticising lowly gearing (even with the manual-box model) and the car’s rather old fashioned feel, it remarked the SL was ideal for “cruising sedately yet quickly” although said the “chassis won’t be remembered for its leech-like road-holding.” However, the monthly rather grew to like the car because it said: “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.”

PRICES

Sam Bailey runs the Worcestershire-based SL Shop, specialising in the car, and has sold well over 350 to happy customers. The UK’s biggest R107 specialist says the rule of thumb is that the newer the car, the more it’s worth, although many enthusiasts coming out of, say an MGB, will find the pre-1986 cars feeling ‘more classical’.

According to Bailey, you should expect to pay more than £10,000 to secure something that won’t need significant expenditure in the near future; this nets a 280SL, 350SL, 380SL or 450SL. If you want a really good 300SL, 420SL and 500SL you’ll pay anywhere between £10,000-£30,000 and possibly even more if it’s a one-owner car with a low mileage.

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

You see a good many cheap SLs on sale and it makes you wonder why specialists want to charge what they do. The answer is, penny to a pound, they’ll be rubbish;  SL Shop’s Sam Bailey rejects far more cars that he accepts. With an SL you get what you pay for and it’s a wise idea to buy the best you can from the outset, as the top ones will always command top money in the future.

IMPROVEMENTS

So well engineered is the SL that tinkering could make the car worse than it is. In fact, be suspicious of cars that have been modified, as the suspension and braking systems are more than suffice in standard form and so are the engines and transmissions in all honesty. And be very wary of SLs ‘blinged’ with non-standard wheels and tyres. Not only do they upset the car’s dynamics but seriously devalue an SL. Tuning parts used to be available but are now hard to come by, and you may need to have the cylinder head and camshafts hand tuned by respective tuning companies if you want more power.

Electronic ignition, if not fitted, and say an uprated radiator, come replacement time, are worthy upgrades. About the only other mod we’d go for is perhaps quality adjustable dampers to reduce the SL’s rather floaty ride – but don’t overdo it.

Audio and security upgrades can be incorporated, while wind deflectors are very popular too; expect to pay around £200 for one from an outfit such as the SL Shop. The same company can also supply rear seats for £299 in vinyl or £425 in leather, while rear seat belts can be offered too.

WHAT TO LOOK FOR

BODY AND CHASSIS

• The SL may be beautifully made, but rot, like any other classic – especially pre-1977 ones. Cars built after benefited from improved rust-proofing, while those made from 1980 featured wax injection. SLs produced from 1986 were also fitted with wheelarch liners and featured galvanised bodyshells
• Start by checking the air intakes at the base of the windscreen, which can get clogged up, leading to corrosion of the bulkhead. Repairs are tricky, and easily cost £1000. The usual giveaway is wet mats in the footwells and a damp, musty cabin.
• Check wheelarches, door bottoms and windscreen surround, all of which can corrode. Of more concern though – and more likely to be rusty – are the jacking points and sills. On pre-1980 cars, take a look at the sub-frame, which can rot badly; replacements are available, but to have a specialist do all the necessary work could easily add up to more than £2000.

TRANSMISSIONS

• Some SLs were offered with a manual gearbox, but these transmissions are best avoided because they’re invariably less pleasant to use and you’ll find it much easier to sell on an automatic. However, the three-speed auto unit fitted to early cars isn’t great, but the four-speeder fitted to post-1980 SLs is much more efficient and transforms the car. However, pick of the bunch is the gearbox that arrived in 1986, which is switchable between sport and economy modes.
• Gearboxes rarely give trouble, but because the 500SL has to transmit so much torque, a rebuild can be needed after around 150,000 miles – expect to pay around £1500 to have the work done. Pre-1975 cars can also be less than 100 per cent reliable, as they featured a fluid flywheel transmission – later boxes employed a torque converter instead. This fluid flywheel could give trouble; if there’s any sign of problems, expect to pay £1500 to right things.

ENGINES

• All are incredibly strong and long-lasting. Failure to change oil regularly will lead to worn camshafts and followers, along with timing chains. Valve stem seals tend to be replaced every 75,000 miles or so.
• If work needs doing, expect to see some blue smoke on start up. If you’re considering a V8 you can also expect to have to fit a new set of tappets, which will add another £600 to the final bill.
• Six-pots were all-alloy, and as a result can corrode internally if anti-freeze quality and mix aren’t maintained but it’s no worse than other classics.■ Other engine-related problems to look out for include a silted-up radiator, which can affect any model – expect to pay around £200 for a re-core. Cars built between 1972 and late 1975 can also suffer from problems with the electronic fuel injection – the Bosch KA system used from October 1975 is more reliable and a bit easier to work on.

RUNNING GEAR

• Dampers go soft and usually isn’t picked up on. All SLs came with power steering. Once 80-90,000 miles have been racked up the box can show some wear but this can usually be adjusted out. However you may have to invest in a box rebuild, which can cost anything up to £1500.
• Brakes are another well-engineered system that gives few problems. All came with servo and discs, many later cars benefit from anti-lock. Are pattern pads are fitted? They tend to rob the brakes of feel.
• It’s a similar story with alloy wheels, as Mercedes used forged parts. As a result, SL’s wheels are durable and, unless they’ve been kerbed, the worst thing you’re have to watch out for is peeling lacquer.

TRIM

• Some later SLs came with refinements such as heated seats and air conditioning, while virtually all cars came with powered windows – only very early examples had hand winders. What you won’t find is a powered roof, as Mercedes never offered one.
• On the subject of hoods, you must raise and stow the roof a few times, to make sure it’s not damaged and that it seals properly. Some never have their roof raised; the hard top either stays on all the time or the car just comes when the sun is shining. As a result, roofs shrink and if you want a new one fitted, you could pay from £600-1200 depending who does it.
• Some SLs came with cloth trim, some with leather, while a fair few were supplied with an MB-Tex finish. This is simulated leather that’s tough and easy to keep clean plus it’s also hard to distinguish from genuine hide.